MUSICAL noun  A play or movie in which singing and dancing play an essential part.

How could I not use “Musicals” for my letter M topic?  I’ve been performing in, directing and choreographing them since I was a child.  Nothing cheers me up like listening to my favorite soundtrack, singing along with abandon and playing all the parts.  I heartily recommend doing this if you are depressed or in need of happiness.  That is all.