All musical instruments can be divided into four major classes: aerophones, chordophones, electrophones and percussion. The biggest and the most versatile class is aerophones which can be further subdivided into free aerophones and pipe aerophones. On the next level free aerophones fall into those with free reed and with beating reed. Beating reed aerophones are represented by single reed (organ pipes) and double reed (human voice) instruments. Free reed instruments in their turn split into those with framed and unframed reed.
Each of these two groups is then subdivided according to the way they are played. Unframed reed aerophones can be wind-blown (bull-roarer, Aeolian harp), mouth-blown(leaf instrument), or mouth-blown-and-plucked (Jew’s harp) while frames reed instruments are mechanically-blown(barrel organ, orchestrion), foot-blown (harmonium, pedal concertina), hand-blown (bayan, accordion), and mouth-blown (harmonica, khaem).
The pipe subclass splits into brass, reed pipe and edge pipe aerophones. Each of them is further divided into two subclasses: brass aerophones into those with (trumpet, French horn) and without (didgeridoo, trombone) valves; reed pipe into single reeds (clarinet, saxophone) and double reeds (oboe, bassoon); edge subclass into whistle flutes (whistle) and tree flutes (flute, piccolo).
The second largest major class of musical instruments is percussion instruments which fall into membranophones and idiophones. Membranophones are subdivided into those with determinate pitch and with indeterminate pitch.
Both of them are then classified by the type of impact: struck (roto drums, snare and bass drum), rubbed (friction drum), and blown (kazoo). Idiophones split into pitched and unpitched and then also include struck (triangle, bell, castanets), rubbed (glass harmonica), plucked (kalimba), and shaken (jingles) percussion insruments. Chordophones have only three primary subclasses: bowed chordophones (violin, cello), plucked chordophones (guitar, banjo), and struck chordophones (piano). The last class of electrophones includes electric/acoustic (electric guitar, bass etc) and electronic insrtruments. Electronic ones then split into electromagnetic (electric organ, synthesizer) and digital (MIDI keyboard, MIDI guitar).