"The atmosphere on Venus shifts the pitch up dramatically (from D Minor to F Minor), making the children sound like Smurfs, while the atmospheres of Mars and Titan transpose the music down (to keys of G-sharp minor and F-sharp minor, respectively), transforming my ten-year old daughter’s voice to that of a large adult. However, while the sound on Titan carries even better than it does on Earth, on Mars the atmosphere absorbs the sound so much that almost nothing is audible when you are only 20 meters from the organ. The calculations indicate what the instrument would sound like at various locations in open -- 'air' -- concert halls on the various planets. One thing’s for sure -- you wouldn’t sell many tickets on Mars!"
They have a short clip adjusted for other atmospheres....take a listen and read the short article