You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Adult_contemporary_music

Context:
Other popular names for the format include "Warm", "Sunny", "Bee" (or "B") and (particularly in Canada) "EZ Rock". The format can be seen as a more contemporary successor to and combination of the middle of the road (MOR), beautiful music, easy listening and soft rock formats. Many stations in the soft AC format capitalize on its appeal to office workers (many of them females aged 25–54, a key advertiser demographic), and brand themselves as stations "everyone at work can agree on" (KOST originated that phrase as a primary tagline, and other soft AC stations have followed suit).

Question:
Along with MOR, easy listening and soft rock, what format is soft adult contemporary a successor to?

beautiful music