Weekend Quick Cryptic 127 - The Hills Are Alive

This time it is my turn to provide the fortnightly Weekend Quick Cryptic crossword, Number 127 in the series. The title "The Hills Are Alive" is a clue to the theme. Can you find all the thematic answers in the completed grid?

You can try and solve the crossword interactively here on MyCrossword or here on crossword.info. As usual you can download a PDF to print which you can find here. Alternatively you can copy and print the image below. Comments and queries are welcome with the solution post (which also gives tips on some of the clues).  I will react to any comments or queries there as soon as I can. You can find an index to the complete series of crosswords here.  

You can find some hints for the perplexed and the solution here and an index to the complete series of crosswords here.