Man, lots of variety here.

Classical piano for 12 years - except for the last half of that, my teacher and I mostly talked and studied 70's progressive rock...
Performed with a pretty big children's choir through elementary/middle school.
Seriously studied trombone for about 6 years through middle school/high school.
Took some bass guitar lessons in high school.
Went to college as a trombone major, but switched to composition as soon as they'd let me. Wrote for weird sized ensembles, unusual instruments.

Now self taught on accordion, drums, guitar, percussion. Work at the University I never graduated from, fixing, building, maintaining electronic gear for the music and theater departments. Do some professional theater sound design work, composing for dance.

I play and have played in a lot of different bands, almost always playing multiple instruments. Currently, a 6-piece folk/rock/chamber band, just stopped playing drums and synths in a 3-piece electro/rock/hip-hop/whatever outfit (they moved), and pursuing a chip project and a non-chip project of my own. I occasionally play low brass for Pomplamoose (the youtube band, not the J. Arthur Keene album).

I am very performance oriented, and have begun working in theater and dance related situations more and more, and concerning myself with costuming and dramatic elements in my music.
Build instruments more and more. I dabbled in chiptunes years ago, and am now getting back into it in a pretty serious way - writing, programming, modding.

Bass since i was 14, thats... almost 9 years. I'm still pretty shit.
Played in some crappy pop punk bands. Then found some jazz guys for a few years.

Also do guitar and banjo (poorly)

I was in a post rock band for a while too.

i got into chip through breakcore

Oh and i had this band where me and a drummer just hit record and jammed http://www.myspace.com/leetcoremusic

I've been playing guitar for about 9 years, keys for 6, and bass for 5.  I've been playing with a band for the last couple of years that's gone through a lot of changes, so we're just now really getting some stuff solidified.

piano - several years

Since then, ive built up a healthy collection of drum machines, synthesizers and fx processors.

Been in a ska band for about 6 years now. (myspace.com/themexicanostrich) We have no good recordings lol, but it's been fun.
I'm been playing drums for about  9 years, and guitar for a good 6. Played Piano when i was a kid, but hated it. I regret not continuing there.
Ukulele is my other love....

5 years guitar. 2 on drums, 2 on analogue noise manipulation. background in a hard rock noise band

I knew nothing about music (well I guess I still do not) when I started messing with LSDJ. a year and a half later I made my first actual track but it was garbage so I never uploaded. Its been a steady building up since then and have only uploaded a few tracks since a lot of the stuff I make is pretty lousy. It is not a real knowledge of music but more like a general feeling. I couldn't tell you why something sounded the way it did or where I placed notes or even reproduce the notes playing on any of my songs. Which is probably the main reason I am having a hard time learning ableton live since the lsdj knowledge is all I have and it doesn't translate well.

I started to take music theory and intonation lessons when i was 8 yrs old. Then i started to play clarinet for 7 years, and one year of piano on classic musical school.
They I started to listen rock music and i moved to the electric guitar, also i liked to learn the other rock instruments, as bass and drums, and obviously, vocals.

I've been singing since an early age.
Learned how to play bass at the age of 12.
After that, I took up the guitar a few years later.
Learned a little bit of drums here and there.
Tried to start several projects but never really went anywhere.
I still play guitar and sing. Still trying to make folk/pop music and other kinds of stuff.

I learned piano for about 3 years when i was around 7 or something. I hated it heaps and wanted to quit. I finally quit and waited a few years, till I went to a new school and a bunch o f kids plaayed guitar. I learned about 3 years ago and I still learn guitar, aswell as chipping.

I can play a trumpet. *nod*

I am grade 7 on cello, and so i naturally took up bass. i am now pretty good with it and have also taken up the guitar

two examples could be this and this

guitar, vocals, got into electronic music making happy hardcore, uplifting trance, and some house-ish kind of stuff. now that i make chip i dont need labels for people to relate to my stuff!

hah :'D  i played some guitar in garage punk band ..