SELECT T2.Name ,  COUNT(*) FROM actor AS T1 JOIN musical AS T2 ON T1.Musical_ID  =  T2.Musical_ID GROUP BY T1.Musical_ID
How many actors have appeared in each musical?
[Schema (values) (types)]: | musical |  musical : musical_id (text) , name (number) , year (text) , award (number) , category (text) , nominee (text) , result (text) | actor : actor_id (text) , name (number) , musical_id (text) , character (number) , duration (text) , age (text);