Roland Pc-300 Into Imac Problems, MIDI USB iMac Options

[amcrory]

Here's hoping someone can help me.

I've got a spanking new flat-panel iMac (800, superdrive, 512mb RAM), and I'm using it mainly for scoring, arranging, etc.

I've got Finale 2003 and Cubasis AV running on it, along with OMS. Finale works fine, as does Cubasis. Both are running in 9.2.2 (not "Classic" mode).

I just bought a new Roland PC-300 49-key USB-MIDI keyboard for it, so I can enter MIDI info, and make my life easier doing scores. It's just a controller -- no onboard sounds. It's USB-powered.

I was hoping (and I KNOW it's possible) to use the Quicktime Instruments synth (in the Mac OS) as my sound source. Mosly I'm just going to use GM/GS sounds anyway... nothing fancy. Some brass, piano, bass, vibes, strings, etc.

I configured OMS, and it seems to be working fine -- it found my Roland without a problem.

So, I plug the keyboard in (USB), and Cubasis shows it's receiving MIDI (the red and green lights in the transport windows flash when I press keys, move the data slider, or the mod wheel). In OMS, when I do a "test studio," I get that funky female voice telling me it's receiving MIDI. So... I know that's OK.

However, I can't get any MIDI sounds to play! Nothing, nada. I have the channel set, the volume's at 127, I'm recording on MIDI channel 1 (and have channel 1 set to a piano sound).... But no playback. Audio sources play back just peachy.

MIDI Thru is enabled, just like the PC-300 manual says. Output through OMS is set for Quicktime Instruments.

What am I doing wrong?

-a