which type of music is this instrument commonly used?
classical music
Saxophone
The saxophone is used in classical music (such as concert bands, chamber music, solo repertoire, and, occasionally, orchestras), military bands, marching bands, jazz (such as big bands and jazz combos), and contemporary music. 
who wrote shake it off by taylor swift Taylor Swift, Max Martin and Shellback. who is this second person mentioned? Karl Martin Sandberg, known professionally as Max Martin, is a Swedish singer, songwriter, and record producer what other bands/singers has he worked with? Britney Spears' when was that track released? August 18, 2014 what are the musical instruments used to play the background of that track? saxophone how would you describe the physical details of this musical instrument? The "straight" soprano and sopranino saxophones consist of a straight conical tube with a flared "bell" at the end opposite the mouthpiece.
wiki:25611349
Saxophone [SEP] Introduction
The player covers or uncovers the holes by pressing keys. The saxophone is used in classical music (such as concert bands, chamber music, solo repertoire, and, occasionally, orchestras), military bands, marching bands, jazz (such as big bands and jazz combos), and contemporary music. The saxophone is also used as a solo and melody instrument or as a member of a horn section in some styles of rock and roll and popular music. Saxophone players are called "saxophonists". Since the first saxophone was invented by the Belgian instrument maker Adolphe Sax in the early 1840s, saxophones have been produced in a variety of series distinguished by transpositions within instrument sets and tuning standard.