piano, n. — Green’s Dictionary of Slang

piano n.

1. a cash register [abbr. Jewish piano under Jewish adj.].

1940s–50s

‘Flann O’Brien’ ‘Standing a Loan’ in Hair of the Dogma (1989) 64: ‘Sairtantly,’ the curate said, taking the cheque and walking up with it to the ‘piana’ (as cash registers are called).

2. (US black) spare ribs; thus piano on a platter, barbecued ribs on a plate [perceived resemblance to piano keys].

1911		J.W. Horsley Memoirs of a ‘Sky Pilot’ 254: ‘Piano’ for ribs of beef, and perhaps ‘churcher’ for a threepenny bit appealed to me as a cleric.
1942		Z.N. Hurston ‘Story in Harlem Sl.’ Novels and Stories (1995) 1003: Good Southern cornbread with a piano on a platter.
1996		Eble Sl. and Sociability 81: Metaphors include forks ‘fingers’ lemon ‘light-skinned black woman’ and piano ‘section of spare ribs’.

3. (N.Z. prison) $1000 [play on SE grand (piano) / grand n. (1)].

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 139/2: piano n. $1,000.

In compounds

piano leg (n.)

(US) a woman with stout legs.

1944

A. Kapelner Lonely Boy Blues (1965) 32: Jelly said: There’s a Piano Leg Mary. Joe said: Hey, Piano Leg! A squat, dumpy girl in gym bloomers ran up to them.

piano player (n.) [he makes the accounts ‘dance’]

(US Und.) a (criminal) accountant.

1973

G.V. Higgins Digger’s Game (1981) 89: He’s got some piano player in there.

rolltop piano (n.)

(US black) a typewriter.

1943

D. Burley N.Y. Amsterdam News 9 Oct. 20: I had a mellow slave, knocking of hen tracks on a rolltop piano.

In phrases

let someone have the piano (v.)

to scratch an opponent's face.

1897

Illus. Police News 11 Dec. 11/2: ‘He is a foreigner — a Jew [...] If he comes to my place i will let him have the piano’ (a slang term for clawing another’s face).

piano player in a brothel (n.) (also pianist in a brothel)

(Aus.) one who is involved in a situation, but adamantly refuses to take any responsibility for it.

1972		Hansard (Aus.) 21 Sept. 1741/2: Mr Bury: Have the trade union leaders paid any more than lip service to decrying violence? Have they taken any effective action, or have they adopted the general, traditional attitude of the man playing the piano on the ground floor of the brothel and affecting neither to know nor care what goes on upstairs?
1981		Australian 4 Apr. Mag. 20: Robert Hughes, art critic for Time magazine, who’s been back on homeground for a month promoting his book on modern art, The Shock of the New: ‘I’m just the piano player in the whorehouse of art.’ [GAW4].
1997		Abilene Reporter-News (TX) Online 🌐 It’s like having the piano player in a brothel tell the vice squad he’s shocked to learn what goes on upstairs.
1998		K.Y. Amoako ‘Governance for a Progressing Africa’ 25 June 🌐 A prominent international news magazine provided the answer, perhaps somewhat inelegantly when last week it stressed that donors ‘… cannot afford to carry on like the piano player in a brothel who pretends not to notice what is going on upstairs.’.
2013		http://emcrit.org 18 Feb. Podcast 93 🌐 This talk lays it out in plain talk and emboldens us to BE A DAMN DOCTOR!, not just the piano player in the whorehouse that is medicine.

play the piano (v.)

to rob the till, e.g. as a barmaid or waiter.

1935		News (Frederick, MD) 15 Feb. 4/8: The bartender’s lexicon reveals a number of new terms [...] ‘playing the piano’ is short-changing the cash register.
1963		B. Naughton Alfie I ii: Ain’t it time you started that fiddle I told you about? Playing the piano on the till.
1979		E. Torres After Hours 207: She’s playing the piano behind the bar.