Mona's, East Village.

The Avenue B Irish dive that runs the city's longest session.

Mona's opened in 1980 in a former Polish dance hall on Avenue B, a block north of Tompkins Square Park. Joe Connolly, an Irish session musician from County Clare, bought the lease and turned it into the East Village's working Irish bar. The bar's central institution is the Tuesday night Irish music session, which has run uninterrupted since 1981. Forty-five years of Tuesday nights. Approximately 2,340 sessions.

The room is long and narrow: a forty-foot bar along the right wall, eight booths down the left, a small raised platform at the back where the session musicians sit. The wallpaper is a yellowed brocade pattern that was beige when Connolly hung it in 1980. The pressed-tin ceiling has not been painted in forty years. The pours are notoriously generous and notoriously cheap.

Why this matters. Mona's is the rare East Village dive that has held its 1980 lease, its 1980 pricing structure, and its 1980 musical identity simultaneously. The session is real. The pours are real. The bartenders are still graduate students who took the job in their twenties and are still here in their fifties.

The Tuesday night Irish session.

Tuesday at 9pm, eight to twelve session musicians arrive at Mona's with fiddles, flutes, tin whistles, bodhráns, button accordions, and the occasional uilleann pipes. They sit at the back platform and begin to play. The session is open: any musician with appropriate technique can sit in. The session is also unbroadcast: there is no schedule of who plays, and the music is not amplified.

The session runs from 9pm until the last musician puts down their instrument, which is usually around 1:30am. The reels and jigs follow a traditional set order that the regular session players know. A guest musician learns the room by listening for two tunes before joining. The Mona's session is the closest thing in New York to a working County Clare pub session.

If you are not a musician, sit at a booth or at the bar with a Guinness. Do not request specific tunes. Do not clap between tunes within a set; clap at the end of a full set, after three to four tunes. Tip the musicians by buying a round for the platform between sets.

Guinness, Jameson, and a hot whiskey in winter.

• Guinness: nine dollars a pint. Properly poured in two stages, settles for ninety seconds, comes with a clean head. The bar's first beer.
• Jameson: seven dollars a shot. The session musicians' chaser. Order it neat alongside a Guinness for the local boilermaker.
• Hot whiskey: eleven dollars in winter only. Powers Irish whiskey, hot water, lemon, cloves, brown sugar. The cold-night drink that Joe Connolly imported from County Clare in 1981.
• Smithwick's: eight dollars on draft. The Irish red ale that the session musicians switch to when they want something between beers.
• The thing nobody knows: the bar will pour a Black and Tan (Guinness over Smithwick's) but only for non-musicians. The session players consider it a tourist drink and the bartenders honor that distinction.

Tuesday at 9pm. Without exception.

Mona's opens at 5pm and closes at 4am. The bar is good every night: the pours are honest, the booths are open, the wallpaper does its work. But Tuesday at 9pm is the only night that matters. The session begins at 9pm sharp. The booths fill in by 9:30pm. The bar is three deep by 10pm. The session ends around 1:30am.

The honest non-Tuesday hour is Thursday at 7pm: the booths are half empty, the bartenders pour slowly, the regulars are reading. Friday and Saturday after 11pm are loud, packed, and the booths require a thirty-minute wait. Sunday afternoon is the secret: the bar opens at 5pm but the regulars filter in by 6pm for slow Guinness and the New York Times.

St Patrick's Day is unmanageable at Mona's. Skip it. The line goes around Avenue B and the music is not the music.

What forty-five years of nicotine and coal fire look like.

The wallpaper at Mona's is a Belle Epoque brocade pattern in a colour that was originally cream. Joe Connolly had it hung in 1980 because it was cheap and looked old. Forty-five years of cigarette smoke and a single coal-burning stove that ran every winter from 1980 to 1995 have stained the wallpaper a deep ochre yellow. The wallpaper is now darker than the wood paneling.

The bar has been offered free wallpaper replacement by three different paint contractors in the last decade. The current owner, Joe's daughter Caitríona, has refused all three. The wallpaper is structural to the bar's identity. It also functions as an acoustic dampener for the session, which is why the music sounds tight in the room despite the lack of a real stage.

For two, sixty dollars across four hours.

Plan for fifty to seventy dollars per person for a four-hour session-night visit. Three Guinness at nine, two Jameson shots at seven, a hot whiskey if it is cold, twenty percent tip. A pair of friends drinks for a hundred and twenty dollars total. The cost of a Tuesday session.

Cards are accepted but cash is preferred. The session musicians get a round bought for them at midnight by the bar's tip pool, and your cash tip on the bar contributes. Three dollars per drink is the local norm.

The session players, the East Village holdouts, the Irish-American visitors.

Mona's draws three populations. The first: the session musicians, a rotating group of about thirty New York-based Irish trad players who consider the bar a working venue. The second: long-tenure East Village residents in their forties, fifties, and sixties who have drunk here since the 1980s and who claim the booth nearest the platform. The third: Irish-American visitors from Boston, Chicago, and Philadelphia who have read about the session and want to attend.

You will find some NYU graduate students, fewer than at Holiday Cocktail Lounge. Mona's clientele is older and more committed. The bartenders take this seriously: Caitríona has refused to take walk-in tour groups since 2015.

How not to be the worst person at Mona's.

• Do not request a tune from the session musicians. The set order is the set order. The musicians do not take requests.
• Do not clap between tunes within a set. Wait for the full set of three or four tunes to end. The musicians will give you a small head nod when the set is over.
• Do not photograph the session musicians without their consent. Caitríona will ask you to delete the photo.
• Do not sit on the back platform. The platform is for musicians only. The bartenders will move you.
• Do not order a Black and Tan if you are obviously a session player. The bartenders will not pour it for you.
• Do not arrive on a Tuesday after 10pm and expect a booth. The booths are full by 9:30pm.
• Do not, ever, request "Whiskey in the Jar." The session players have heard it enough times. They may play it eventually. Do not be the person who asked.

Veselka, McSorley's, Mona's. The session-night route.

The classic East Village session-night route: pierogis at Veselka on Second Avenue at 6pm. Walk three blocks south to McSorley's at 7:30pm for two pairs of Dark and a cheese plate. Walk five blocks east to Mona's at 9pm for the session. Arrive at 8:45pm to claim a booth before the music starts.

For more bars in the area, see our New York city guide, the live music bars guide, and the East Village hidden gems list.

Yes. The most musical dive bar in New York.