Possible Clues:

• Like musical instruments
• Adjusted (musical) pitch
• How one French female got to sound right with one in the Dail around
• The noted racing engine needs to be this to perfection
• Adjusted the radio knob
• Composed new duet with desired pitch
• Fixed a flat?
• 'And many a thing may hap ere -' (William Morris)
• No longer flat
• With improved reception