9A: Split up part of guitar (4). The answer is clearly FRET - but what does this have to do with Splitting, or Splitting Up? Is it intended to be an "&Lit"? If so, it's extremely obtuse...
15D Don't waste time worrying about this as a "6,3". It's a "9". TLS seems particularly capricious in this area. (e.g. last week's DRTHORNE (7)) 19D Charles Johnson's pseudonomous...