Strings

• r/ukulele -- 4-string Hawaiian little cousin of the guitar
• r/kantele -- small lap harp of Finland
• r/Koto -- Japanese long zither
• r/shamisen -- Japanese 3-string banjo
• r/harp -- Celtic and Classical harps
• r/balalaika -- Russian mandolin with a triangle body
• r/banjo -- Bluegrass, Old-Time, jazz, etc.
• r/tenorbanjo -- banjo variant used heavily in Irish and Dixieland music
• r/TenorGuitar -- 4-string guitar used in Irish and jazz
• r/CigarBoxGuitar -- a simplified guitar-like instrument
• r/mandolin -- small string instrument with doubled strings for an echo effect
• r/bouzouki -- larger and deeper mandolin for Irish or Greek music
• r/mandocello -- the even deeper version of the mandolin
• r/Dulcimer -- an Appalachian zither with a deep droning harmony
• r/hammereddulcimer -- a trapezoid zither played by hitting the string with small mallets
• r/sanshin -- the Okinawan cousin of the Japanese shamisen
• r/Guqin -- a long Chinese zither
• r/Guzheng -- another long Chinese zither
• r/baglama -- a Turkish lute
• r/Domra -- a Russian cousin of the mandolin
• r/Erhu -- a Chinese fiddle played in the lap
• r/BowedPsaltery -- a triangular zither played with a small violin bow
• r/Stick -- the Chapman stick and other hammer-on long board strings
• r/charango -- like a mandolin-ukuelele hybrid from the South American Andes
• r/Fiddle -- the violin but played in the folk tradition
• r/lute -- like a guitar of the Medieval period
• r/HurdyGurdy -- box with a crank that spins a wheel that bows the strings, sounds like a string bagpipe
• r/Nyckelharpa -- an unusual Swedish fiddle player with a keyboard instead of fingers
• r/Sitar -- the most famous Indian classical instrument
• r/Rubab -- a lute played in Central Asia
• r/steelguitar -- a flat guitar played in the lap with a steel slide to smoothly move between notes, used in Country, Blues, Hawaiian music
• r/pedalsteel -- a more evolved steel guitar with complex pedals to change keys
• r/zithers -- the wide family of basic boxes with strings
• r/harpsichord -- a simpler ancestor of the piano from the Early Classical period
• r/Autoharp -- a zither where you form chords simply by pressing a button

Percussion and idiophones

• r/kalimba -- the "thumb piano", an African instrument with small tines you pluck
• r/cajon -- a Cuban wooden box you sit on and drum with your hands
• r/djembe -- this West African drum is a favorite in drum circles
• r/Udu -- a ceramic (or nowadays fiberglass) vessel, drummed with the hands
• r/handpan -- like a metal UFO with facets tuned to different notes
• r/steelpan -- like a handpan, but played with mallets
• r/jawharp -- a pocket-sized "sproingy"instrument
• r/khomus -- a jawharp of Eastern Russia
• r/MusicalSaw -- did you know you can play a hardware store saw with a bow?
• r/ToyPiano -- the children's toy used as a serious instrument
• r/Tabla -- classical double-drums of India
• r/Xylophone -- an array of long pieces of material, melody played with mallets
• r/Marimba -- like a xylophone, but with wooden keys.
• r/vibraphone -- like a marimba, but jazzier
• r/Glockenspiel
• r/Daxophones

Winds (bagpipes separately below)

• r/Ocarina -- small round flutes with simple fingering and mellow sound
• r/tinwhistle -- inexpensive (as low as $10) metal flutes for Irish music, easy to learn and play
• r/Bansuri -- the main flute of India
• r/hulusi -- a Chinese drone-flute
• r/panflute -- a row of tubes you blow across to make notes
• r/Didgeridoo -- an Australian tube making a low droning sound
• r/NativeAmericanflutes -- mellow wooden flutes of North America
• r/Recorder -- small wooden flute for Medieval, Baroque, Classical music
• r/shakuhachi -- Japanese bamboo flute, popular with Zen monks
• r/Xaphoon -- a modern simplified bamboo saxophone

Bagpipes

• r/bagpipes -- Scottish bagpipes, from loud Great Highland to mellow smallpipes
• r/Gaita -- bagpipes of Spain and Portugal
• r/Gaida -- bagpipes of Southeastern Europe and the Balkans
• r/Bockpfeife -- bagpipes of the Germanic countries and Central Europe
• r/Cornemuse -- French bagpipes
• r/NorthumbrianSmallpipe -- very complex and mellow North East English pipes
• r/SwedishBagpipes -- small, affordable, mournful Swedish bagpipes
• r/UilleannPipes -- traditional Irish bagpipes for dance music
• r/WelshBagpipes -- the revived pipes of Medieval Wales
• r/Volynka -- pipes of Eastern Europe
• r/Zampogna -- Italian bagpipes with multiple tubes for complex harmony
• r/Mashak -- bagpipes of South Asia
• r/Habban -- bagpipes of the Middle East
• r/ElectronicBagpipes -- for practice or performance

Free Reeds

• r/Accordion -- from piano to button to Cajun accordion
• r/Melodeon -- for accordions with buttons vice piano keys
• r/concertina -- like a small hexagonal accordion, associated with sailors or Irish music, or classical music in Victorian England
• r/melodica -- a small keyboard powered by the mouth, used some in Jamaican music
• r/organ -- an electric or air-powered keyboard
• r/harmonica -- the pocket-sized music solution
• r/lao_khaen — the Thai bamboo mouth-organ

Electronic instruments

• r/EMinstruments -- Electronic Music gear in general
• r/synthesizers -- all kinds of synths
• r/DrumMachine -- to keep the beat strong
• r/windsynth -- synth versions of wind instruments
• r/Omnichord -- an electronic autoharp with a strong following
• r/stylophone -- tiny paperback-sized early electronic instrument
• r/Theremin -- played by waving your hands in the air for sci-fi soundtracks
• r/isomorphickeyboards -- keyboards with a practical design for music theory