Green’s Dictionary of Slang

goola n.2

[ety. unknown]

(US black) a piano.

[US]D. Burley N.Y. Amsterdam News 15 Jan. 17/4: One of the best goola thumpers in the country.
[US]D. Burley Orig. Hbk of Harlem Jive 12: Those gams, ole man, are like the props on a goola.
[US]Berrey & Van den Bark Amer. Thes. Sl. (2nd edn).
[US]Wentworth & Flexner DAS.