Green’s Dictionary of Slang

tune n.

In phrases

play a tune on the meat whistle (also ...the skin flute)

(US) to fellate.

[US]T. Berger Sneaky People 305: ‘[P]lay a little tune on my meat whistle. Don’t bite, and maybe I'll slip you a dime’.
[US]D. Fulmer Blue Door 65: He would have shacked up with her in a flophouse. That’s what he really wanted. And not just to [...] play a tune on his meat whistle whenever he felt lonely.
to some tune (adv.)

to a substantial extent.

W. Hazlitt ‘On the Aristocracy of Letters’ in Table-Talk II 104: [T]he Poet and the Peer agree to honour each other’s acceptances on the bank of Fame, and sometimes cozen the town to some tune between them.
[UK]Music Hall & Theatre Rev. 16 Feb. 11/1: ‘[S]ince my arrival [in Australia] I have scooped the boodle to some tune’.