7string said:
It's an instrumental track. Drums, bass, 2 acoustic guitars, piano, strings and flute. The drums, bass and guitars sound great until I bring in the piano. Then the guitars get lost and basically all you can hear is the pick on the strings. I've done some basic EQ'ing (my favorite thing - blech!) and managed to get everything sounding better but because of the way it was played, some of the piano notes are lost. He's not really playing chords but more like little arpeggio's and ramblings on the keyboard. It's mostly the lower-mid notes that tend to disappear. Does that help any?
Acoustic guitar and piano combos can indeed be tough to mix because they share so much sonic space.
It'd be hard for me (or anyone) to give specific advice without being able to hear the mix and the arrangement (hint hint

), but at this point I'd be wondering about four things:
1. I'd still persue the idea of using automation to try and bring up the weak piano parts. But I'd also look at it from the other side (see #2).
2. Is it possible to bring the guitar parts down temporarily? I've done many instrumental mixes with multiple acoustic guitars and multiple keyboards, and one nice technique I've found for playing automation tricks with track volumes in dense arrangements (assuming you're using a DAW editor) is to listen to the individual tracks and for each track mark points where a particular fill, riff, mini-arpeggio, or other cool hook or sound appear. Then, when you reach that point in the timeline, bring the track with the good section up just a couple of dB and (when necessary), simultaneously bring the other competing tracks down just a couple of dB.
We're only talking a 1.5-3dB raise or drop per track which, if done right, is not readily noticable to the listener, However the differential between the two track volumes at that point, 3-6dB, is plenty to cause one instrument to stand out over the other at that point. It's a neat trick of using volume to accentuate hooks and/or weaker parts of tracks without causing a "noticable" volume change.
This technique requires a little more work than usual, but it's kinda fun (IMHO, and really one of my favorites), can really make a dense or busy mix sound like it has a lot more room than it really does, and often yields far more flexible, apporpriate, and natural sounding results than just applying a blanket coat of dynamics control over entire tracks.
3. Is there any flexibility on the part of the artist as far as the arrangement of the song parts? Sometimes less is more; a mix can sometimes work better not to have all tracks armed at all times during the song. Hand off between the gits and the keyboards at times, whether for just a bar or for a verse (or chorus or bridge), or use a little call and response between them, so that they are not just stepping on each other all the time.
4. Going back to basics, keep like-sounding instruments panned away from each other when possible. They don't have to be an entire stage apart (please, let's keep hard-pans in the bag for a change

), but keep the acoustic that sounds most like the piano a bit to one side and the piano a bit to the other, to keep them distinct somewhat.
HTH,
G.