Clinton: What synth are you using for the various tracks? As rharv points out, you need to use a unique instance of the synth on each track (and I would assign unique midi channels to them as well) where you have a MIDI part.

Also, as robh points out, as soon as you are happy with a midi track, record it's output to a stereo .wav track and use that .wav track as where you apply effects. Turn off the corresponding midi track, of course.

Also, as a mixing tip: If you have lots of instrumentation going on including the piano, sometimes it's best to subtract out the low frequencies of the piano rather than to try to add to mids/highs for the piano. Apply a little panning to that track and that might be just the trick to get it to stand out in the mix.

The problem with an 'all hands on deck' piano part, when mixed with a band, is that the piano covers frequency content across most of the spectrum that the rest of the band is playing in. Let each part do it's part. Acoustic guitars are also guilty of this; sometimes the best thing to do is simply cut the lows on an acoustic track that's in a mix and voila, it becomes 'brighter' without boosting anything. The mud gets removed from the mix.

-Scott

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