List of musical instruments by Hornbostel–Sachs number: 421

Edge-blown aerophones is one of the categories of musical instruments found in the Hornbostel–Sachs system of musical instrument classification. In order to produce sound with these aerophones, the player makes a ribbon-shaped flow of air with their lips (421.1), or their breath is directed through a duct against an edge (421.2).

421.1 Flutes without duct – The player creates a ribbon-shaped stream of air with their lips.

421.11 End-blown flutes – The player blows against the sharp rim at the upper open end of a tube.

421.111 Individual end-blown flutes

421.111.1 Open single end-blown flutes – The lower end of the flute is open.

421.111.11 Without fingerholes.

421.111.12 With fingerholes.
 * Anasazi flute
 * Danso
 * Hotchiku
 * Kaval
 * Ney
 * Nose flute
 * Palendag
 * Quena
 * Shakuhachi
 * Sring
 * Suling
 * Tungso
 * Washint
 * Xiao

421.111.2 Stopped single end-blown flutes – The lower end of the flute is closed.

421.111.21 Without fingerholes.

421.111.22 With fingerholes.

421.112 Sets of end-blown flutes or panpipes – Several end-blown flutes of different pitch are combined to form a single instrument.
 * Diple

421.112.1 Open panpipes.

421.112.11 Open (raft) panpipes – The pipes are tied together in the form of a board, or they are made by drilling tubes *in a board.

421.112.12 Open bundle (pan-) pipes – The pipes are tied together in a round bundle.

421.112.2 Stopped panpipes
 * Pan flute
 * Siku

421.112.3 Mixed open and stopped panpipes.

421.12 Side-blown flutes – The player blows against the sharp rim of a hole in the side of the tube.

421.121 (Single) side-blown flutes.

421.121.1 Open side-blown flutes.

421.121.11 Without fingerholes.

421.121.12 With fingerholes
 * Bansuri
 * Chi
 * Daegeum
 * Dangjeok
 * Dizi
 * Fife
 * Gakubue
 * Kagurabue
 * Junggeum
 * Komabue
 * Koudi
 * Minteki
 * Nohkan
 * Ryuteki
 * Sáo
 * Seiteki
 * shinobue
 * Sogeum
 * Western concert flutes
 * Piccolo
 * Concert flute
 * Alto flute
 * Bass flute
 * Contra-alto flute
 * Contrabass flute
 * Double contrabass flute
 * Hyperbass flute

421.121.2 Partly stopped side-blown flutes - The lower end of the tube is a natural node of the pipe pierced by a small hole.

421.121.3 Stopped side-blown flutes.

421.121.31 Without fingerholes.

421.121.311 With fixed stopped lower end - (Apparently non-existent).

421.121.312 With adjustable stopped lower end

421.121.32 With fingerholes.

421.122 Sets of side-blown flutes.

421.122.1 Sets of open side-blown flutes.
 * Paidi

421.122.2 Sets of stopped side-blown flutes.

421.13 Vessel flutes (without distinct beak) 	The body of the pipe is not tubular but vessel-shaped.
 * Jug

421.2 Flutes with duct or duct flutes - A narrow duct directs the air-stream against the sharp edge of a lateral orifice

421.21 Flutes with external duct - The duct is outside the wall of the flute; this group includes flutes with the duct chamfered in the wall under a ring-like sleeve and other similar arrangements.

421.211 (Single) flutes with external duct.

421.211.1 Open flutes with external duct.

421.211.11 Without fingerholes.

421.211.12 With fingerholes.
 * Native American flute

421.211.2 Partly stopped flutes with external duct.

421.211.3 Stopped flutes with external duct.
 * Boatswain's call

421.212 Sets of flute with external duct.

421.22 Flutes with internal duct - The duct is inside the tube. This group includes flutes with the duct formed by an internal baffle (natural node, bock of resin) and an exterior tied-on cover (cane, wood, hide).

421.221 (Single) flutes with internal duct.

421.221.1 Open flutes with internal duct.

421.221.11 Without fingerholes.

421.221.12 With fingerholes.
 * Atenben
 * Flageolet
 * Fujara
 * Khloy
 * Khlui
 * Recorder
 * Tin whistle
 * Tonette

421.221.2 Partly stopped flute with internal duct.

421.221.3 Stopped flutes with internal duct.
 * whistle

421.221.31 Without fingerholes.

421.221.311 With fixed stopped lower end.

421.221.312 With adjustable stopped lower end.
 * Slide whistle

421.221.4 Vessel flutes with duct.

421.221.41 Without fingerholes

421.221.42 With fingerholes
 * Gemshorn
 * Ocarina

421.222 Sets of flutes with internal duct.

421.222.1 Sets of open flutes with internal duct.

421.222.11 Without fingerholes - Open flue stops of the organ.

421.222.12 With fingerholes
 * Double flageolet.

421.222.2 Sets of partly stopped flutes with internal duct.

421.222.3 Sets of stopped flutes with internal duct.
 * Paixiao