Wiktionary
detune
vb. 1 (context music English) To intentionally lower or raise the pitch produced by a musical instrument. Often done to produce sounds not normally possible, or in the case of stringed instruments to reduce tension for the purposes of shipping or maintenance. 2 (context electronics English) To alter the capacitance of a circuit such that its resonant frequency differs from the incoming frequency.
Usage examples of "detune".
Finally he reached for the lute, detuned it, and put it back in its traveling case.
Sentient cope with it all, but frankly, another detuning might be their last.
Then Withen flushed as Vanyel stooped quickly and caught up the neck of his lute, detuning it with swift and practiced fingers and stuffing it quickly into its traveling bag.