BBC Music Magazine 234

[anikomo]

I am completely stuck on final 3 clues and would really appreciate help.
11a. Instrument's limit to harmonisation? (4)I have ?O?N
20a. Leading performers accepting position back in new companies?(5-3) I have ?T??? U?S
18d. Youngsters' piano equipment taken on board. (6) I have S???G?

[Lie-in King]

20a Start-ups - 'put' (position, back, in) 'stars'
18d Sprigs - p(iano) + 'rig' (in) SS (ship, so "on board")

[anikomo]

Thank you both,very much, for your invaluable help. I am really grateful.

[boxtops]

11 - horn?

[Euphemia]

11a horn

[anikomo]

Thank you also, boxtops and Euphemia For your great help.