Sit down at a session and within a minute you will hear four or five instruments doing quite different jobs. Some are carrying the melody, some are holding the room together underneath it, and one or two are doing something in between. Here is what each of them is, what it sounds like, and how to pick it out by ear.
The two jobs in the room
Irish traditional music is overwhelmingly melody-led. The tune is a single line, and any number of players can play that same line together — which is why a session can absorb three fiddles and two flutes without anything going wrong. Harmony is optional, comparatively recent, and held to a supporting role: a guitar or bouzouki fills in underneath, a bodhrán marks the pulse, and the melody stays king.
That structure is worth knowing before you start identifying instruments, because it explains the social rules around them too — melody players double up freely, accompanists take turns. Our session etiquette guide goes into why.
The melody instruments
Fiddle
Physically the same instrument as a violin; musically a different discipline. The trad fiddle sound is drier and more rhythmic than a classical one, with ornaments flicked in rather than sustained, and much less vibrato. It is the most widespread instrument in the tradition and the one with the strongest surviving regional accents: the driving, heavily bowed Donegal style with its Scottish-influenced highlands; the flowing, ornament-rich Sligo style familiar from early twentieth-century recordings; the more lyrical, unhurried playing associated with Clare; and the bouncing polkas and slides of Sliabh Luachra on the Cork–Kerry border. Two fiddlers from different counties playing the same tune can sound noticeably unalike.
Tin whistle and low whistle
Six holes, a fipple mouthpiece and, usually, a body in D. The whistle is where a huge proportion of Irish musicians start, because it is cheap and immediately playable, and it stays in the hands of serious players for life — the ceiling is far higher than the price suggests. Listen for the breathy attack on each note and for ornaments produced by flicking a finger rather than by the tongue. The low whistle, pitched an octave down, is the darker, airier sound used for slow airs and film music.
Flute
Not the silver orchestral instrument but the simple-system wooden flute, keyless or with a few keys, and usually pitched in D like the whistle. It has a woody, breath-driven tone and a strong rhythmic bite, and flute playing leans heavily on ornaments made with the breath and the fingers — cuts, taps and rolls — since the instrument cannot bend a note the way a fiddle can. In a session the flute is often what you hear cutting through the room.
Uilleann pipes
The Irish bagpipes, and the most complicated instrument in the tradition. Air comes from a bellows strapped to the elbow rather than the mouth, so a piper can talk, or sing, while the bag stays full. A full set comprises the chanter that plays the melody across two octaves, three drones supplying a continuous background note, and three regulators — keyed pipes the player can chord against the melody with the side of the wrist. Beginners generally start with a practice set of bag, bellows and chanter and add the rest over years.
The pipes are the sound most listeners recognise as unmistakably Irish from records by groups like The Chieftains and Planxty. Live, they are worth going out of your way for: a full set in a small room is an experience no recording quite delivers.
Button accordion and melodeon
The two-row button accordion — a “box” — is one of the loudest and most common melody instruments in the tradition. It is bisonoric: each button gives a different note pushing and pulling. Tunings vary, with B/C and C#/D the two you will hear most, and they encourage noticeably different phrasing, which is why box players argue about them. The single-row melodeon is its older, more limited cousin and has a distinctive rolling lift. The piano accordion turns up too, more often in céilí bands and country music than in a session corner.
Concertina
Small, hexagonal, and quieter than it looks — the Anglo concertina, usually in C/G, is the type used for Irish music, and like the box it sounds a different note on the push and the pull. It is strongly associated with Clare and with a light, ornamented, rhythmically springy style. In a crowded session a concertina can vanish under a bodhrán, which is one reason players get particular about volume.
Tenor banjo and mandolin
The four-string tenor banjo, tuned in fifths like a fiddle an octave lower, arrived through American popular music and settled permanently into the tradition. Played with a plectrum, it gives a hard, staccato, percussive version of the melody that is instantly recognisable and very good at cutting through noise. The mandolin does something similar an octave up and blends more easily.
The accompanists
Guitar
A twentieth-century addition, and now near-universal. Trad guitarists rarely use standard tuning; DADGAD and dropped-D are the common choices because they make drone-like open strings easy and suit the modal shape of the repertoire. A good session guitarist is almost inaudible as a separate thing — you notice the tune has a floor under it, not that someone is strumming.
Irish bouzouki and cittern
Adapted from the Greek instrument in the 1960s and 70s, the Irish bouzouki is flat-backed, with four pairs of strings, often tuned to something with an open fifth or an open octave in it. It sits between rhythm and melody: chopping chords under a reel one minute, doubling the tune the next. If you hear something that sounds like a very large mandolin, that is what it is.
Piano and keyboard
Not a session fixture, but a long-standing part of the wider tradition — the vamping piano behind a céilí band is one of the defining sounds of Irish dance music on record, and the harmonium and keyboard do the same job in some groups today.
Rhythm
Bodhrán
A goatskin frame drum, struck with a short double-ended stick — a tipper or cipín — while the other hand presses against the inside of the skin to change the pitch and damp the tone. Played well it is subtle, shifting under the tune. Played badly it flattens everything above it, which is why sessions can be wary of one turning up unannounced.
Bones and spoons
Two curved pieces of bone or wood held in one hand, or a pair of spoons back to back, rattled against the knee. Old, portable and capable of real virtuosity in the right hands.
And the harp?
The harp is the national emblem and the oldest emblematic instrument of Irish music, but it is not a typical session instrument. The wire-strung early Irish harp — the instrument of the old professional harpers — largely died out and has been revived by specialists, while the modern lever harp you are most likely to see is a concert and teaching instrument. You will hear harp at recitals, in concert programmes and at festivals more often than in a pub corner, and it is well worth seeking out; the repertoire it carries is different from the dance tunes.
What to listen for once you can name them
The interesting part of Irish music is rarely the notes of the tune, which are usually simple, but what a player does around them. Listen for rolls (a note broken up by rapid flicks above and below it), cuts and taps (single grace notes used percussively), cranns (a piping and flute ornament used where a roll is impossible) and the way individual players push or hold back against the pulse. Two players can play precisely the same melody and one will lift the room while the other does not.
Tune types are the other useful vocabulary. In rough order of how often you will hear them:
- Reel — four beats to the bar, fast, the backbone of the session repertoire.
- Jig — a rolling six-eight; the slip jig is its longer-limbed nine-eight cousin.
- Hornpipe — four beats again, but swung and deliberately heavier.
- Polka — brisk two-four, strongly associated with the Cork–Kerry borderlands.
- Slide — a loping twelve-eight, likewise a southwestern speciality.
- Waltz, mazurka, march, set dance — less frequent, but all in circulation.
- Slow air — free in rhythm, usually solo, often derived from a song. The room should be quiet for it.
Hearing them for yourself
None of this survives reading about it. The fastest education is a few hours in a room where the instruments are in front of you: watch which hand is doing what, and the sounds separate out quickly. Our guide to what actually happens at a session explains how those rooms work, and telling Irish music genres apart covers where the dance-tune tradition sits alongside ballads, sean-nós and everything else.
When you are ready to go, Explore lists what is on across the country tonight and over the coming weeks, the venues directory shows what individual rooms have coming up, and you can follow the artists whose playing you take to so their next gig comes to you.