A multi-instrumentalist is a musician who plays two or more musical instruments at a professional level. Multi-instrumentalists who play closely related instruments, a practice known as doubling are common in orchestra (e.g., flute players who double on piccolo and percussion players, who play snare drum, cymbals, bass drum, etc.), in jazz (e.g., saxophone players who double on clarinet or flute; or double bass players who also play electric bass); in music theatre pit orchestras (e.g., reed players who are required to play numerous reed instruments); and in other areas of classical music (e.g., church piano players are often expected to play the church's pipe organ or Hammond organ as well). Popular music composers and songwriters are often multi-instrumentalists. In pop and rock, it is more common than in classical or jazz for performers to be multi-instrumentalists on instruments that are not from the same family: it is common for pop and rock musicians to play both guitar and keyboards. Many bluegrass musicians are multi-instrumentalists. Some musicians' unions or associations specify a higher rate of pay for musicians who double on two or more instruments for a performance or recording.
The European Piffari, Stadtpfeifer and Waits were multi-instrumentalists, who played trumpet, sackbut, shawm, cornett, recorder and string-instruments. Musicians with an education of a Stadtpfeifer were Gottfried Reiche,Johann Joachim Quantz, Johann Christof Pezel and Sigmund Theophil Staden. Also many European church musicians of the 17th and 18th centuries were multi-instrumentalists, who played several instruments. Georg Philipp Telemann for example played violin, viola da gamba, recorder, flauto traverso, oboe, shawm, sackbut and double bass.