My dad once said to me, "There's no better deal than buying sheet music."  This is still true.  I recently purchased a Peters Edition of Bach's Goldberg Variations.  Looking at this and listening to Glenn Gould perform the piece really inspired me to get back some of my "Classical" chops.  All for about $20.  (The CD cost me $1.  Amazingly, I found it in a Salvation Army bin!)

All this said, there is a place for open source sheet music for editions and compositions that have passed into public domain.  One of those places is The Mutopia Project, where you can find a PDF and a MIDI file all sorts of music, such as the second fugue in The Well Tempered Keyboard.  

If you followed that link, you may have noticed that you can also download the LilyPond file.  What's that?  It's one of the things that makes me so excited about the site.  All the music is written in the GNU Project's LilyPond language.  It's a little like HTML, where a simple text file can be rendered as a beautiful graphic.  Being a programmer and a musician can having it's advantages!

The thing I like about having the text "source" file for the score is that if I know LilyPond, I can change the way the finished output looks.  Take our fugue from above.  It is very unadorned, which is good if you're not a beginner and you want to interpret the music on your own.  (This is something Peters Edition is good about.)  

We pianists write our fingering and expressions on the paper music.  This is fine most of the time, but what if you want to publish an edition yourself?  Or say you are a piano teacher who wants her students to have sheet music with her interpretation?  Marking up the music each time is tedious.  But with a few changes to the text source, the score could look like this:

Since I edited this myself, there's no copyright on it.  I'm free to email a PDF to my friend or, as I did here, make a PNG picture of it and post it on a website.  If you wanted to know how this sounds and you're not a pianist, you could create a MIDI file from the source.  Or, like the people at Mutopia, you could find old, public domain editions and make them available to everyone.

How about custom piano lessons?

If this doesn't sound exciting to you, that's okay.  We programmers just like to compile things.

You don't have to know comedy improv to be an improv piano player.  But it helps.

In improv (the acting kind) there is something called "pimping".  This is when you put your fellow comedian on the spot, either by giving them some unusual attribute (endowing) or calling for some difficult action ("Show us that dance routine you've been working on!")  For beginners it's considered bad form, but experienced improvers will do this all the time.  You may have seen the TV show Whose Line Is It, Anyway? where one by one the actors come to a party and are given some unusual trait?  It's like that, but unexpected.

So how does knowing this improve your performance as an improv musician?  Say you hear this on stage:

"I'm so happy to be a Bloboslovian!"

"That's great.  Hey, how does that national anthem go again?"

Player One is being pimped.  The first rule of improv is, you never deny the situation.  Player One needs to start singing.  Of course he or she can do this a capella but even better is for you to start playing some stately chords of the Bloboslovian national anthem.

In a sense, you're being pimped too.  Player Two is saying, We need to hear a song now! and it's up to you to provide it.  Why?

There's a scene in the movie Who Framed Roger Rabbit? where Eddie (the detective) and Roger have been handcuffed together for a while.  Eddie is awkwardly filing at the chain and Roger slips off his side of the cuffs to help.  Eddie, incredulous, says, "You mean you could have taken those off at anytime?"  "Not at anytime," says Roger, "only when it was funny."

This is one of your guiding precepts: play when it's funny. If someone on stage wants to hear Bloboslovian national anthem, you play Onward, Bloboslovia.  If someone gets arrested, maybe you play the theme to Dragnet.

But only if it's funny.