That's right, 2006. Shortly before my 20th birthday, while living at home with my parents working on books and other resources for a music-instruction business (focused on the bluegrass/old-timey music that we play), I had an idea: what if I wrote a computer program that was like a metronome, but instead of playing "tick tick" it played realistic guitar sounds by assembling individual guitar samples?
I hacked together a proof-of-concept app in Visual Basic .NET shortly thereafter. It strummed either a G chord or a D chord at the tempo you chose... and that's it. Not particularly useful... but audio-wise, it worked.
But at the time, I had several other projects on the fire, so I got distracted and didn't work on it any further. Besides, my programming skills were not very advanced at the time so I probably wouldn't have been able to make anything that great anyway.