Brice Martin
Brice Martin is the professional musician who recorded, among other things, the Ressikan flute melody played by Jean-Luc Picard for the  episode . He played the melody on a pennywhistle.

Martin's web page states that he has recorded not only for The Next Generation,  but for Deep Space Nine, Voyager, and Enterprise, as well.

External links 
MartinsMusicStudio.com – official site
Chiff and Fipple – The Star Trek Whistle Mystery Solved (StarTrek.com)
Martin, Brice