The Bachelor of Music degree usually requires a second instrument to be learned (unless one is studying composition), but people who double on another instrument (e.g., guitar and piano) are not usually seen as multi-instrumentalists.
In most cases, a multi-instrumentalist will play several types of keyboard and plucked string instruments, such as piano, synthesizer, organ, guitar, bass and mandolin, and perhaps also percussion and drums. They may also play brass and woodwind instruments, although this is fairly rare within popular music. The voice is sometimes, albeit rarely, listed amongst a multi-instrumentalist's instrumental repertoire.
Some musicians have pushed the limits of human musical skill on different instruments. The British entertainer Roy Castle once set a world record by playing the same tune on 43 different instruments in four minutes. Anton Newcombe, frontman for The Brian Jonestown Massacre, claimed in the documentary film Dig! to be able to play 80 different instruments.
Multi-instrumentalist Yuri Landman not only plays several string instruments, but also creates several new instruments with alternative scalings, constructions and string combinations to reach new playing techniques. His work is mainly based on resonance, string pitching and overtones.
A number of artists have become well known for their proficiency on many instruments. Some examples include: Ian Anderson, David Bowie, Phil Collins, Stewart Copeland, Graham Coxon, Jay Easton, Ben Folds, Daniel Gildenlöw, Jonny Greenwood, Brian Jones, John Paul Jones, Paul McCartney, Marcus Miller, Neal Morse, Mike Oldfield, Prince, Trent Reznor, Emitt Rhodes, Sufjan Stevens, Elliott Smith, Steve Winwood and Stevie Wonder .