Capo

I can't play that song without a capo.

If you find it hard to memorize advanced guitar chords, you can use a capo and play the common chords in other keys.

The mafia's capo ordered his men to get rid of the supposed snitch.

[…] the capo in a sub-camp in 1940. As a foreman and capo in the quarry he earned the reputation of treating Jewish[…]