IN 1971, John Lennon wrote a letter to a young singer/songwriter named Steve Tilston after reading an interview in which Tilston expressed worry about becoming too successful and losing his authenticity. Needless to say, that didn't happen to Tilston, whose name you've just heard for the very first time. Tilston didn't receive the letter—a warm, supportive note that included Lennon's phone number—until 2005.

Danny Collins presupposes the songwriter did become a success and did lose his authenticity. Al Pacino's the songwriter, burned out on drugs and women and fame. He trots out a "Sweet Caroline"-like number called "Hey, Baby Doll" every night for admiring, graying ladies; he's engaged to a young, empty-headed floozy; his soul is dead inside. Pacino's pretty okay at playing a guy who's sick of being the center of attention, but the rest of Danny Collins is wretched. After discovering Lennon's letter, Danny decides to get his life on track by tracking down his long-lost son (Bobby Cannavale), writing the first new song he's written in 30 years (it's about autumn leaves), and attempting to bed a Hilton hotel manager (Annette Bening).

But this is a bullshit movie that takes place in a bullshit world where all concerts are one song long, all long-lost sons turn out to have terminal diseases, and all adorable granddaughters have learning disabilities that can only be cured by throwing rock-star sums of money at them. Lennon would be sickened.

DEPT. OF CORRECTIONS—An earlier version of this review misstated the name of the hotel chain that employs the fictional character played by Annette Bening. Bening's character is, in fact, employed by Hilton, not Ramada. The Mercury deeply regrets the error. The Mercury also deeply regrets having to devote any more space and time to Danny Collins, which, again, is a movie that you should not see.