The Mephisto Waltz
Alan Alda plays a classical piano player on the rise who befriends a famous player himself who's at death's door. Unknown to Alda, the guy is a satanist, who arranges to have thier souls switch places at his death, so that he can be young again and continue to play piano (thus needing a skilled piano player like Alda to switch bodies with).
Alan Alda, Alberto Morin, Anabel Shaw, Antoinette Bower, Barbara Parkins, Berry Kroeger, Bradford Dillman, Curd Jürgens, Curt Lowens, Frank Campanella, Gregory Morton, Harry Carter, Jacqueline Bisset, Jeffrey Sayre, Kathleen Widdoes, Khigh Dhiegh, Lilyan Chauvin, Marta Kristen, Pamelyn Ferdin, Pitt Herbert, Terrence Scammell, William Windom