Circlegram

Replace the question mark at the centre of this puzzle with a letter, so that the letters within each circle can then be re-arranged to form three words linked by a common theme. What are the three words in this week’s circlegram? What is the letter represented by the question mark at the centre of the puzzle?

SOLUTIONS TO LAST WEEK’S CIRCLEGRAM:

The letter represented by the question mark is N. Saxhorn, melodeon, mandolin, all musical instruments.