Possible Clues:

• Working in stone is a strain
• Mental or emotional strain
• Nervous strain apparent in notes played
• At a stretch this makes it XX X to the North
• Sounds as if one is taught that XX + X gets to the North
• XXX is enough to make the North tight
• One isn't put out by it, but it's a strain
• One isn't properly treated for strain
• Massage target
• One isn't (anag.)