From 1969-1970, adult entertainment impresario Hugh Hefner - who turns 91 today - hosted Playboy After Dark, a swanky TV show that invited viewers into Hef's rumpus room, where one of the biggest rock acts of the day would serve as the party's house band. The acting was brutal, but the live music was often sensational.

Here are the best musical performances from 'Playboy After Dark.'

1. The Grateful Dead

Cannabis icon Jerry Garcia was still in mourning when he chatted with Hef before The Grateful Dead's set on 'Playboy After Dark.' In October 1967, members of the counterculture officially put the Summer of Love to rest by marching through Haight-Ashbury and other neighborhoods of San Francisco with a coffin symbolizing the Death of the Hippie - a demonstration to raise awareness that the counterculture was about a frame of mind, not a specific time and place.

"Haight-Ashbury is just a place," Garcia told Hefner. "It's just a street. It's not really the thing - it never was the thing that was going on. It was the thing people could talk about because it was easy to remember."

The Grateful Dead then performed 'Mountains on the Moon' and 'St. Stephen' live.

2. Tina Turner

The 'Ike and Tina Revue' episode of 'Playboy After Dark' was pretty sedate until Tina riled up the crowd with a rollicking cover of 'I Want to Take You Higher' by Sly and the Family Stone.

For their second set, Tina belted a "greasy" version of The Beatles' 'Come Together'. "When you say grease, it means getting down to the nitty gritty" in music," Tina explained to Hef between retaking the stage. She also performed 'Proud Mary' and The Rolling Stones' 'Honky Tonk Women'.

3. Deep Purple

Deep Purple were a little too far-out for Hef's comfort when they stopped by the rumpus room in 1969 and shared a spooky experience with Hefner's guests. 

"I understand that you all moved into a house together so that you could live together and work together, but it didn't work out," Hefner said. "What happened?"

"It was haunted," keyboardist Jon Lord explained while wearing dark sunglasses inside.

"You really believe it was haunted?"

"I know it was haunted," a spacey Lord insisted. "I saw it with my own...glasses."

"I'm not gonna ask you the circumstances under which it became possible to see all those strange manifestations," Hefner added awkwardly before asking the band to play their breakout hit 'Hush'.

4. The Byrds

Unfortunately, not all the bands that appeared on 'After Dark' performed live. (We're looking at you, Three Dog Night.) Some didn't even try to lip synch convincingly. (Your ears should be burning, Iron Butterfly.)

But that only makes the truly live sets all that much better. Especially with bands like The Byrds, who stopped by the show to do what they did best - smoothing out the edges of Bob Dylan's hits.

Here they are performing Dylan's 'You Ain't Goin' Nowhere' and 'This Wheel's on Fire' (which was co-written with RIck Danko of The Band).

5. Fleetwood Mac

Technically, the legendary rock group performed as The Fleetwood Mac as Hef flubbed their intro. But the group took the misnomer in stride, performing 'Rattlesnake Shake' with the band's original lineup of Peter Green, Jeremy Spencer, John McVie, Danny Kirwan and Mick Fleetwood.