Sandy & Danny,… uh,..I mean John Travolta and Olivia Newton-John have collaborated on a Christmas album that features special guests like Tony Bennett, Barbra Streisand, and Kenny G.  The album, This Christmas, marks the first time Grease‘s Sandy and Danny have recorded music together in nearly 35 years. According to a release, Travolta got the idea to make the record “after receiving a Christmastime text from his old friend Olivia noting that their 1978 smash, ‘You’re the One That I Want,’ had just become the best-selling duet in pop music history.”   Travolta and Newton-John will donate the album’s proceeds to their respective charities — the Jett Travolta Foundation, which works to combat children’s disabilities, and the Olivia Newton-John Cancer and Wellness Centre in Melbourne.  The album is due out Nov. 13th!