Here's what we know about episode 7.
The official press release
Rock Never Dies” — (9:00-10:00 p.m. ET) (TV-14, DLV) (HDTV)

RICK SPRINGFIELD ROCKS OUT AS LUCIFER – Lucifer (Rick Springfield) realizes that as rock star Vince Vincente, he can get his fans to do whatever he wants. Thrilled with this power, Lucifer arranges to play a secret VIP concert in order to kill all of them. Sam (Jared Padalecki), Dean (Jensen Ackles) and Castiel (Misha Collins) enter the underbelly of the music industry to try to stop him. Eduardo Sanchez directed the episode written by Robert Berens (1207). Original airdate 12/1/2016.
The preview
 An interview with Jensen, Jared and Misha from TV Addict  (may contain spoilers for episode 8 as well.)
The sneak peek
 The promo pictures
 So Rowena's banishment to the bottom of the see didn't last very long. Lucifer gets summoned and has his body repaired? And then discovering that all kinds of important people will do what he wants decides to kill them all off? That doesn't sound very smart. We do get Rick Springfield as Lucifer again, which I'm happy about, although the TV Addict interview makes it sound as if he doesn't stick around very long. What do you think? Are you glad to see Rick back as Lucifer? Will Sam, Dean, Castiel and Crowley manage to stop Lucifer from murdering all Vince's and his fans? Tell us in the comments or in the discussion thread for episode 7.
ETA: The writers found a good way to keep Mary in the story without using Samantha Smith. Good for them.

AdmirorGallery 5.2.0, author/s Vasiljevski & Kekeljevic.