Verb
retune (third-person singular simple present retunes, present participle retuning, simple past and past participle retuned)
To tune again.
After the long first movement, the orchestra had to retune.
By moving leather tuning rings up and down the neck, a kora player can retune the instrument into one of four seven-note scales. Source: Internet
Pitch can be varied with no restraints and adjusted in the midst of performance, without needing to retune. Source: Internet