As for Ozzy singing In My Life, obviously his voice isnt up to par for that song. But I think he did it because I read somewhere that he is a huge Beatles fan, and I think I may have even read that when he first got into music, he wanted a band like them. Someone correct me if I am wrong.
And I will say I really like Alanis' version of Dear Prudence. I don't care for that song, but I think she did a great job, I enjoyed listening to it!