Sunday, May 17, 2020

Phil's Rules of Guitar

I have been playing guitar for more than 20 years, quite avidly for most of them. From the start, my goal has always been to be able to pick up a guitar and play songs with feeling.

Throughout the years I've found great personal reward from playing and singing and writing songs. I love finger picking, jamming, strumming, flourishing, sweeping, rocking out, and very occasionally djenting. The most influential guitarists in my personal pantheon are David Gilmour, Joe Satriani, and Stevie Ray Vaughan; although there are many, many players who have influenced my songs and technique. From Curt Kirkwood, to Frank Zappa, to Fink; Django to Eric Johnson, Suzanne Vega, Paul Simon, B.B., Tom Waits, Elliott Smith, Jason Isbell, Jimi, Joe Pass, Brendon Small, Blaze Foley, Bootsy, Queensryche, The Beatles, Ben Folds, MFSB, TMBG, The Allmans, David Bowie, Bonnie Raitt and far too many others to ever encapsulate in one trifling list.

I've met a lot of players, taught a few lessons, love experiencing live shows, and listened to an awful lot of music. I think anyone can become a better player. I think the satisfaction of playing songs is its own reward, and I believe that if you are lucky enough to share your music with other people that is a wonderful experience. Maybe the defining experience of a lifetime.

All of this is to say that while I certainly don't know everything about playing the guitar, I know a few things. I know that many people wish they could improve their playing, or learn to pick up and play at all. I say to you all that it is very achievable. I'm happy to share the exercises and experiences that are part of my technique, but first I'll share my foundation.

I follow three very simple rules in guitar, and when I am being self-critical and want to improve, the first thing I ask myself is how true I am being to them.

I absolutely guarantee* that if you follow these three rules your playing will immediately improve.

Phil's Three Rules of Guitar

  1. You Play What You Listen To
  2. Know Your Tuning
  3. Tap Your Foot

You Play What You Listen To

I was almost eighteen when I first started playing guitar and I took some lessons from a cat named Greg Greenwald - and if you think it's pretentious to refer to him as a cat and not a dude or a player or a person, you haven't met him. He's the quintessential cool cat, and that's that. Greg eventually moved to Austin and I haven't heard from him in decades, but in my formative years he showed me some pretty important things.

In my time with Greg I picked up chords, chop builders, string bends and even my first formal exposure to the twelve bar progression. But the most important thing he ever taught me was on our first lesson when he asked what I wanted to learn on the guitar. I told him my hero was David Gilmour, and Gilmour always talked about the blues so that's what I wanted to learn. So Greg asked me what blues music I listened to, and I had no answer. I listended to classic rock, alternative, and metal mostly. That's what was on the radio.

"How are you ever going to learn to play the blues if you don't listen to blues music?", he asked me incredulously. From that point on every lesson included a listening assignment. Seek out the three kings, he told me at first. B.B., Freddie, and Albert all have unique tones and they sound more different than they do alike, but they all play the blues. Learn to tell a Texas shuffle from Chicago style - delta blues from gospel - dirty blues, medicine bottle slide, and horn arrangements. Be able to tell Guitar Slim from  Johnny "Guitar" Watson. Listen to more B.B., and hear how his band and arrangements change throughout all those live albums but the songs can be the same.

Eventually he played some Stevie Ray Vaughan for me and that set me on a course for quite a few years. Robert Cray once said, "for a long time coming there's going to be a lot of frustrated guitar players trying to pick up on Stevie's stuff." And he sure nailed it.

If you want to play Texas blues, you have to listen to the folks who invented it and the music that inspired them. If you want to learn swing jazz, put on some Louis Armstrong, Count Basie, and Duke Ellington. If you wish you could play Flamenco you have to learn the language of the music. You have to feel those songs, not just read the changes from a fake book, or pick up a new strumming technique and hope it sounds like Flamenco.

Know Your Tuning

If you can't tune your guitar your playing won't sound good. It is natural when you play for strings to stretch or even slip a little and this changes the pitch. If you can't tell when your strings are drifting out of tune your playing won't sound good.

A guitar's standard tuning is (low to high) EADGBE. Being able to pick up a guitar and tell if it's in tune is the single most fundamental aspect of performing on the instrument. An electronic tuner is a good way to get started and keep yourself playing, but if you play in standard tuning, you should quickly come to understand that the interval between most of the strings is different than the interval between the B and G string. Maybe it will help you to know that those intervals are a fourth and a major third respectively, but maybe it won't. Those labels aren't the sound.

You can learn to tune without an electronic tuner by knowing which frets on adjacent strings line up with the open string (5, 5, 5, 4, 5 - low to high). You can learn to sound harmonics and hear the waves go in and out of phase when the same harmonic note is struck on two different strings. To get a guitar properly in tune, you just need a reference tone. I like to use an A tuning fork, but most metronomes can generate an A at 440 hz. You can also type "A 440" into google and find hundreds of sources online.

There is a lot of music written and transcribed for standard tuning, but that doesn't mean people always play this way. People retune their instrument. Frequently. Some of your favorite songs may be in alternate tunings. In standard tuning the open, jangly chords are E and A, with G and C relatively simple shapes to learn. You'll quickly find that an open D chord is a little different, because it only uses the top four strings, and this can be limiting or difficult to strum at first. But if you drop the low E string a whole step to D you can strum a very jangly open D or make power chords on the low strings with just one finger. This is called dropped D tuning, and you might enjoy trying it, or its somewhat underused cousin, double dropped D (found by tuning down both E strings) to write and learn songs.

Many horns, however, don't tune to E or A or D, but to B flat. If you want to play with horn players, it might eventually occur to you to use a capo, which is a device that clamps over the neck of the guitar and shortens the string length - effectively tuning your instrument upwards in pitch. Putting a capo on the 1st fret makes the open keys F and B flat. People use capos to allow for familiar chord shapes and changes in other keys while keeping their guitar in relative tune.

This is all still correct playing. Players find tunings that help them express themselves through song. If you love Joni Mitchell's songs, and want to play them, you'll quickly learn that she used dozens of alternate tunings. A musician might prefer open C, open G, or DADGAD. Pete Townsend liked to change the tuning of his guitars as a way to make familiar chord shapes sound new and interesting. Kim Thayil had this to say about alternative guitar tunings:
Well, the whole drop-D tuning thing was probably popularized in Seattle as a consequence of our success. And we couldn’t be stagnant and just stay there, so we started playing around with other tunings. We liked the fact that what we were playing didn’t sound like what our friends and peers were playing. So we started introducing things like open slide tunings into our songs. Then we had what we called the “digga digga” tuning, which was drop-D with the A string dropped to G. That really took off for us around [1991’s] Badmotorfinger. And also the [low to high] E E B B B B tuning that Chris and Ben used on [1994’s] Superunknown. [This tuning can be heard on Superunknown cuts like “My Wave” and “The Day I Tried to Live.”]

Stevie Ray Vaughan liked the tone of thicker, heavier strings and would tune every string on his guitars down a half step to reduce the tension on the neck. Metal players like to take this further and tune down a whole step, or even play in dropped D down a whole step to dropped C in order to produce a darker, booming sound.

What matters is being aware of the intervals you leave between strings, and keeping the pitch of the strings consistent. As your ear gets sharper you might find that at certain points on the neck of your guitar, even when the electronic tuner says the string is correctly tuned, the pitches of the strings don't quite line up. This is a natural result of string gauge, intonation, and fret placement, and there's no way to truly have your guitar perfectly in tune at every point on the neck. Many people have tried to solve this problem, so if you're fascinated by this idea go read about tempered tuning and maybe check out the Buzz Feiten Tuning System.

You have to know how your guitar is tuned to create good sounding music, but that doesn't mean you have to play in standard tuning.

Tap Your Foot

The third rule is so simple I'm almost embarrassed to share it. Almost. So many players learn to play and only listen to the clicks of a metronome, or play without anyting at all to keep their tempo steady. Then they are shocked to hear that their playing is slowing down and speeding up when they play with a band. Tap your foot to the music. Do it when you're listening, and definitely do it when you're practicing and playing. Tap to a metronome, tap along to recorded songs, tap your foot when you jam with another player. This simple act engages wholly different parts of your brain and locks you into the groove.

If Al Di Meola practices foot tapping, so can you.

Thanks for reading, and keep on practicing!

* not a guarantee

Saturday, September 12, 2015

Just A Quick One (While He's Away)

Today's post will be about relational databases. Are you familiar with the PostgreSQL history file? Have you ever wondered about its contents? I mean, probably not, unless you've had to do some deep digging on the topic of recovery in Postgres. There's not much too it, but I had a difficult time finding the specifics when I went looking, so here shall they be published.

I have a few goals in mind for this weekend (wait, it's Saturday afternoon already? Well, you know, the rest of this weekend):

  • build my first presentation with reveal.js for my upcoming talk at Postgres Open in Dallas
  • watch the Green Bay Packers win their season opener tomorrow at noon
  • crush my foolish opponents in Fantasy Football
But those can all wait until I relate to you this story. Imagine you are a database administrator. Now, some of you may not know what a database administrator (dba) does, but that's not too hard. A developer writes code, a sys admin keeps the data center running, a manager makes it possible for these people to work without interruption; but you're supposed to imagine being a dba. A dba worries only about the database.

To make the database happy a dba will always want one of a few things:
  1. More space. Database admins are always going on and on about how there's not enough space, and the business should learn how to archive old data, and has anybody ever heard of a Data Warehouse?
  2. An upgrade. Most dba's seem to think that by getting "new features" and "performance improvements" they will somehow find contentment. But they will never be content, because the new Alpha has a newer feature.
  3. More RAM and more cores. Always.
  4. More space. Yes, the database just kept growing while I was writing this, and we don't have enough room for all these backups. Tell me where to move these backups, and so help me if you say /dev/null I will slug you.
One day you are presented with an opportunity. You can migrate the database to a new server where you will be given more space, more memory, more compute and a chance to upgrade to the newest version. Hoisted by your own petard, you must now perform the migration with minimal downtime.

But you run the world's most advanced open source database in PostgreSQL, and that's not actually a very hard proposition if the database is on version 9.0 or newer! Version 9.0 came out almost exactly five years ago, so hopefully you are somewhat with it. And I'm not judging if you're not, but you need to catch up. Unsupported databases and Production environments just don't mix.

Anyway, in version 9.0 PostgreSQL implemented streaming replication, which has since become the de facto standard for enterprise database availability. Streaming replication is a powerful feature which allows you to build a readable clone of your production database, that keeps up with changes rapidly. Just how rapidly can depend on many factors, but that's not the point of this story.

In this story, you enable streaming replication from your primary (the old database server) to your new hardware. On the night of the cutover, when you're ready to upgrade, you: stop web traffic for a few minutes, promote your replica to master and shut down the old service (don't want anybody connecting to that), run pg_upgrade -k to upgrade without copying a bunch of files around (no backing down now), start the new cluster, and analyze your tables. If you've built a nice maintenance window in, you might take the time to VACUUM some big tables or rebuild bloated indexes while nobody's connected, but it's not a must. When you're done, the app starts up, and whoever was responsible for changing all the connection strings (wait, was that your job? I thought chef would handle it. . .) did so, and the app is now happy because the database is happy.

If you're really good at your job, you've practiced this a few times before doing it for realzies to make sure there are no quirks to the upgrade process, but eh. If you want to walk on a tightrope in your imaginary career as a dba, that's your problem. You can take it up with the imaginary CTO after you have to roll back four hours in because you hadn't realized the extension system changed between 9.0 and 9.4, and now this new production database won't load data because of "citext"!? *

Everybody is happy. The production app is running, and you can now set up a new streaming replica from this, the new primary, since the laws of high availability dictate you should have at least two of everything. You sync the data directories for the first time, eager to start up your replica, only it won't start. It complains:

ERROR:  could not open file "pg_xlog/00000002.history": No such file or directory
FATAL:  could not receive timeline history file from the primary

What happened? In fact, PostgreSQL has - or rather had - a bug of exactly this fashion. When PostgreSQL promotes a new primary server, it creates a marker of the timeline split in the form of a small text file placed in the WAL file directory. This file makes it possible to achieve Point-In-Time-Recovery under some rather complex failover and fail-back scenarios. It cannot, however, be used to recover to a point in time before the upgrade, and it knows this. So pg_upgrade deletes the .history file. This isn't a problem for the operation of the new primary. But it makes it impossible to start a streaming replica, for lack of a file that's probably less than 100 bytes. Or at least, it did before Bruce Momjian patched the bug and back-ported the fix through 9.0

But before that you were stuck. If you spend some time reading the recovery documentation you may come across recovery_target_timeline and think that setting this to 'latest' will help. But it doesn't. Instead it makes the replica think there is a newer history entry, and it will just start complaining about wanting "pg_xlog/00000003.history" now. So it seems that you will have to recreate the file. You can find a very nice summary of the .history file on the Postgres wiki. Since the info is in .pdf, though, it tends to be harder to index, so you may have trouble locating the doc if you don't already know it's there.

Which brings me in a rather roundabout fashion to what I asked at the very beginning of this entry (how long ago was that? Good god, Lemon): are you familiar with the internals of the .history file? Probably not, but they're very simple. A numbered history file contains an entry for each previous point in the WAL record where a new timeline began. Sound hard? It's not.

# cat 00000002.history
1 1404/A0000017 Some comments about when the timeline split.

That's it. One digit, a magic number, and some comments. Now about that magic number..? If we actually needed the ability to recover back to a different timeline, we'd need the correct address. But we're never going to go back to that timeline, because it's before our upgrade. All we'd need to recreate a lost file is a good enough number. And you can get one by running:

# SELECT pg_current_xlog_location();
(1 row)

Mock up a .history file in your WAL directory with these values, et voila. The replica will immediately be able to start.

Be seeing you!

* Please note that upgrading extensions from pre 9.1 versions of PostgreSQL is generally a very simple matter, and I don't mean to imply that you'll have problems with citext or any other extension. Generally, the toughest thing you'll have to do is download a patch and run CREATE EXTENSION <<extension>> from UNPACKAGED; 

And you can handle that. Just don't wait until the night of the upgrade to find out you need a patch and have to start looking. Plan ahead, imaginary dba. Gosh.

Sunday, September 6, 2015

The Lesser of Two Evils

I am confronted with a mountain of paper every time I sit down at my desk. I look just over it, most of the time, and stare instead at the left monitor, which of the pair has always been primary. The paper isn't scary, or difficult, and going through it would probably be of enormous personal benefit. It's at least half comprised of unopened credit card applications, scattered with actual correspondence, and densely packed with various credit card receipts.

It is these receipts that I am most trying to avoid. The easiest way to avoid them would be, of course, to stop getting receipts with most of my purchases like a normal person; and just balance online from time-to-time. But I can't do that, because I am my father's son, and I require a paper confirmation of purchases to balance against the creditor's computer or the merchant, because either of them could make a mistake.

Except I don't actually do the balancing anymore. I used to do it - enter paper receipts into a spreadsheet, and account for each line by line against the various cards' balance page - about once a week, for a period of several years. It was tedious. It was laborious. And it was truly productive. In absolute dollar value for time, it's probably the most productive thing I could do, because it forced me to account for every purchase - what it was, and what it cost - and eventually, I learned how to spend less than I made. But it didn't feel productive. It felt like work, and I avoid that whenever possible, so I stopped.

Anyhow, I choose the next easiest way to avoid something, and that's to tune it out. The mind really has no problem forgetting the details of our immediate surroundings. One of the major functions of the brain in crafting our perceptions into consciousness is to ignore all of what is deemed inconsequential, like most of the visual input we actually receive. In fact, it's incredibly common to fail to notice when our surroundings change, because we spend most of our time shucking our short term memory for a useful bit that could go onto long term memory.

Though, to digress for a moment, we actually have quite a poor understanding of what the brain deems useful for storage, or why. Consider for a moment, the case of the poor lady who one night while drifting to sleep suddenly, and without warning, began to hear full song arrangements - as if from a radio in the back of her head - endlessly looping. Sometimes the same snippet for weeks. She knew some of the tunes, but for many others she was both unable to recall having heard them ever before, and powerless to stop them playing.

So I can ignore this paper pile, is what I'm saying. And also, the brain is messed up. Really, really messed up sometimes. But at this moment, the pile is spilling over the bottom of the screen, making it tough to see my start bar. Which means I am constantly being tricked into looking at the pile when I mean to click on the PowerShell icon. And no, I'm not ashamed to run Microsoft's flagship OS, though I increasingly ask myself why exactly I'm doing it when Linux really does do almost every individual piece a little bit - and sometimes a lot - better (except stitch it all together into one convincing experience, I guess).

I think the receipt problem is the most important outstanding personal problem I have yet to solve. Or really even acknowledge. By writing this post, I have successfully not opened any of the mail, or signed up for to see if it could help me. At the moment, the solution I've arrived at is to write a simple web front-end that lets me enter receipts into a database of my design. Honestly, a dedicated coder with the slightest understanding of web forms could prototype this thing in an afternoon. Yet I have also successfully not written this seemingly trivial app in Python, or Node.js, or Phoenix, or vue.js. Which are all unquestionably awesome ways to do such things.

But now I'm at the bottom of the page, and I have to keep leaning to the right to see around the pile when I'm at the beginning of the line. :-(

Be seeing you!

Saturday, August 22, 2015

Where We Came In

☯ To begin is everything. Without beginning, without ever hitting "Publish", this blog is just unfinished drafts staring at me and only me. Taunting me :-|  I love my words, but I cringe at my writing, so things just sit.

Still, I can be cromulent, so I will write briefly (yeah right!) about who I am, and my life, and the things. For starters, this is the personal blog of Philip Eugene "Phil" Vacca. I am a Milwaukee native, the father of one beautiful girl, and a Purdue Boilermaker (by way of UWM & IWU). So stop telling me how good the Badgers are. I know already. I play the guitar when I'm inspired, and the banjo when I'm relaxed. I should like to see the Earth's great megaliths, starting with Göbekli Tepe. I bathe in the light of many monitors all day and all night, and if I'm producing something useful it probably has to do with data, and the problem of why there's so much of it yet so little knowledge or wisdom.

To that end, if you're looking at this entry some time before September 16th, 2015, it's not too late to travel to Dallas, TX for Postgres Open! It is quite a gathering of minds in the open source database world, and this year I am thrilled to be a speaker!

Before I further digress, let me say that the thoughts and opinions expressed on this page are now and will always be my own. They do not reflect and should not be mistaken for the opinions or beliefs of any entity with which I may be employed or otherwise affiliated.

So, all that said, who is Six, and why is he for Two? More to the point, Who is Number One? This is, of course, a reference to one of television's great masterworks, The Prisoner - itself the single minded vision of Patrick McGoohan, who created the show with Lew Grade. I will hopefully take the time some day to explain why I love this show, and what lessons it holds for contemporary viewers; but for now, it's enough to say that it matters to me. And that Six For Two is the campaign slogan of the man who preferred not to say why he resigned.

I imagine this space will end up with an awful lot of talk about computers and computering, and not nearly enough about Pink Floyd or stone age Earth or the Green Bay Packers. It's some sort of inevitable rule. If you use computers - I mean really use them - half of all time you spend on the internet will be devoted to reading about computers and how to better instruct them. The internet pretty much sprang up around astronomers and Unix geeks writing down what they were doing, so it's no surprise that there is essentially limitless reading to be done on the subject(s). The only way to avoid spending all that time reading about computers is to write something about them.

But this isn't a technical piece, it's just an exercise in getting to a published thing. So, while I haven't even gotten to reminiscing about my early interest in computers, which was my original intent, it has gotten quite late and it's a shame not to at least try to dream a little.

Be Seeing You!