Green’s Dictionary of Slang

1. conversation, chatter, talk, esp. defiant, aggressive, cheeky talk.

1821–6		‘Bill Truck’ Man o’ War’s Man (1843) 92: Yon’s a blarney – mere claver and chin music – that gaed out at the ae lug as fast as it cam in at the ither.
1831		Satirist (London) 31 July 135/1: [H]e has turned out a three-days’ wonder, like Mick Boai, professor of chin-music , or Doctor Pearson , the whistling Dean.
1838		D. Crockett in Meine Crockett Almanacks (1955) 125: Says I, give us none of your chin music.
1844		‘Jonathan Slick’ High Life in N.Y. II 108: I thought [...] to give ’em a short specimen of Weathersfield chin music.
1857		in Journal of Discourses V 101: Whenever he attempts to amuse them with his chin-music, they expect that he will say something funny.
1859		Wkly Varieties (Boston, MA) 3 Sept. 4/3: Will the Chief of Police give this boy-policeman a little ‘ chin music’ in regard to his duty.
1865		North Amer. Rev. July 296: ‘Chin music’ we venture to call it.
1876		Besant & Rice Golden Butterfly II 206: ‘I am not,’ he said, ‘going to orate. You did not come here, I guess, to hear me pay out chin music.’.
1877		H. Hartigan Stray Leaves (1st ser.) 17: Their wonderful peformances which went under various denominations from ‘chin-music’ to ‘slack-jaw’.
1884		‘’Arry at a Political Pic-Nic’ in Punch 11 Oct. 180/1: But, bless yer, my bloater, it ain’t all chin music.
1889		World (N.Y.) 3 Aug. 3/1: They [...] kicked till the umpire assessed McKean $25 for too much ‘chin music’.
1890		Sporting Times 22 Feb. 2/2: It transpired that we could have done without all this chin music.
1895		Truth (Sydney) 2 June 3/4: I called on my friend the Barber [...] to get my customary threepenn’orth of chin music.
1904		Sun. Times (Perth) 10 Jan. 4/5: He and Toby Barton were members of the same debating society at Sydney university [...] George took to chin-music as naturally as a duck to water.
1908		B. Fisher A. Mutt in Blackbeard Compilation (1977) 61: His keen intellect active brain and abnormal capacity for chin music.
1910		‘Doss Chiderdoss’ ‘With Music’ Sporting Times 8 Jan. 1/3: She told three or four / Just what she thought about it, with music, I’m sure, / The descriptive sort known as chin music.
1913		S.F. Call 22 June 6/5: I should be havin’ t’anks instead o’ chin music.
1922		M.E. Smith Adventures of a Boomer Op. 60: If his chin music had been morse he’d had Barfield looking like a cadet in a ‘Ham Factory’.
1936		C. Sandburg People, Yes 90: I don’t believe a word you say but I love to listen [...] to your chin music.
1943		R.L. Bellem ‘Dead Man’s Shakedown’ in Dan Turner Detective Mar. 🌐 It gives us a chance to fling some chin music without interruption.
1944		P. Kendall Dict. Service Sl. n.p.: chin music . . . talking.
1955		B. Schulberg On the Waterfront (1964) 132: Knock off the chin music.
1960		(con. 1940s) G. Morrill Dark Sea Running 155: Knock off the chin-music, Navy.
1999		Seattle Central Community College On-Line News 5 Dec. 🌐 Did you know? [...] Other ‘chin’ expressions for loose lips include ‘chin-music’ (a noun meaning ‘idle talk, chatter’), ‘chinfest’ (another noun synonymous with ‘chat’), and ‘chin’ itself (which can be used either as a verb meaning ‘to chatter’ or a noun meaning ‘a chat’).
2004		Guardian Sport 1 Mar. 22/3: Vaughan [...] confessed yesterday to knowing very little about Lawson, but expected the orchestration of ‘chin music’ to be no less intense.
2005		Mad mag. Aug. 38: Dubya’s good ol’ foreign policy chin music.

2. (US) promotional copy; persuasive writing.

1902

C.L. Cullen More Ex-Tank Tales 135: Some feller that’s a good ink slinger an’ thet kin spread good chin music on paper.