as a jazz player, I've been using arrangers (Korg is35, Technics kn2600, Gem genesys ProS) and pretty much kept to the bass/drums/percussion except for using the full
arrangements sparingly as a little added color on some tunes. I've been been thinking I could live without the full accompaniments altogether and might have a better choice of KB's if there were any that could provide bass lines w/chord recognition..are there?

In short: Yes, it can be done.

Most of today's workstations have pretty flexible arpeggiator section which can be used to provide full blown accompaniments. It is tricky to set up though.

I've never actually bothered with this stuff myself since I prefer sequencing to any kind of monkeying around with arps and accompaniments. But I know people who don't mind setting up arps on their Motifs, Tritons and Phantoms so its not rocket science.

-ED-