Jazz players have a long history of playing along with recordings, whether to transcribe a solo and learn to play it exactly how it was played on the record or to just jam along. Since I have split my time pretty evenly between jazz and classical I have done quite a bit of this. I just recently realized that it is at least as helpful for my classical playing as my jazz. I have always worked on phrasing by singing along with recordings, but it is completely different to actually play and try to perfectly match with your horn. I've learned quite a bit of subtle things in my playing in the last week from playing along with guys like Maurice Andre, Reinhold Freidrich, and Matthias Hofs. I think I will sit in with the Chicago Symphony tomorrow and see how well I can blend with Bud (this is where having a huge stack of orchestral parts comes in handy).