15d. Being in fashion, tour guide goes round outskirts of Mali's ancient city. (9) P?U???I??
17d. After being told to turn over a new leaf, state that it can be a source of poisoning. (8) ?T???I??
24a. Queen's basic vocal has Mercury starting but then doesn't use all five vowels. (5) ??A?? - the 'A' could be wrong.
Thank you for any help.