I'm a semi-retired musician and music has always been a big part of my life so I'm a bit picky when it comes to what I listen to. And my preference whether smoking a pipe or not is progressive rock - for the uninitiated it's a combination of rock and classical - examples would be bands like YES, Genesis, Emerson Lake & Palmer, Jethro Tull, Pink Floyd, The Moody Blues and a whole lot of others from a variety of countries. I don't even mind when bands sing in their native tongue. I have tons of bands from Italy, Germany, Poland, Sweden, Hungary, Japan - any country where there are progressive rock musicians making and recording music. Lets be honest, half the time it's hard to understand what some vocalist are saying anyway, so as long as they sound good I don't mind. But my preference is instrumental progressive music, which was the type of music I composed when recording under the moniker Ghosts Of Pompeii. It's easier to let your thoughts drift while listening to instrumental music and enjoying a bowl of your favorite tobacco.
And for that reason my second favorite music to listen too while smoking is movie soundtracks. And by one composer in particular - Bernard Herrmann. You may not recognize the name but I'm sure you've heard his music from Hitchcock films like "North By Northwest", "Psycho", "Vertigo", "The Man Who Knew Too Much"; fantasy films like "Mysterious Island", "Journey To The Center Of The Earth", "The Three Worlds Of Gulliver", "The Day The Earth Stood Still", "It's Alive", "The Ghost And Mrs. Muir", "Seventh Voyage Of Sinbad", "Jason And The Argonauts", "Fahrenheit 451"; and film classics like "Citizen Kane", "The Devil And Daniel Webster", "Jane Eyre", "Taxi Driver", and "Hangover Square" to name a few.
And like fellow piper 'abcbill', I too enjoy Mannhiem Steamroller's Fresh Aire series of eclectic New Age albums, as well as the German electronic synth band Tangerine Dream. All great music to listen to while puffing on a pipe.