simple or compound sentence?

[df2006]

Dear all

1. Mary played the piano and sang a song.
2. Mary played the piano, and she sang a song.

I know the above sentences have the same meaning, but structurally speaking, can I say that sentence (1) is a simple sentence while sentence (2) is a compound sentence since there are TWO SUBJECTS and two verbs (although both SUBJECTS refer to the same person)?

Thanks.

[Barb_D]

Yes, the first one has a compound predicate, and the second is a compound sentence.

[df2006]

many thanks for clarification.