I think we’d have to call this one a miss as well. While there are amazing advances in computer aided music, it is hard to claim that musicians “jam” with computers. Of course, there are some cool games (like Guitar Hero and Rock Band), but those can hardly be called “jamming”. There are also new sound systems, pitch correction software, advanced rhythm machines, etc. I think the closest thing you could get to here would be DJs that use advanced machines to link and bridge songs in really sophisticated ways.
But again, it would hardly be considered a “jam.” Kurzweil was wrong again.