I'm pretty sure Storch played all the keys on DYWM, but couldn't really do the whole touring thing at the time... and he had projects of his own to work on. he still works with the roots... he wrote the "you got me" melody and yes that was him on letterman... gotta give props to the dude who composed it!! for those who don't know... he's the mastermind behind the Still D.R.E. melody and works with the jazzyfatnastees and plenty of others... he actually played keys on the boogie monsters' underwater album (i'm a liner notes nerd) and i'm pretty sure he worked with spearhead as well.