Bob Marley's son played a 'fully solar' concert at Apple headquarters on 4/20

Twitter/Tim Cook

• Apple holds a social event called "Beer Bash" on Friday afternoons at its headquarters.
• This year, to celebrate Earth Day on April 20, it booked Ziggy Marley, a reggae musician. 

One of Apple's longest-running traditions is called "Beer Bash." Basically, on Fridays, employees can gather in the courtyard inside the company's headquarters, grab a beer or two, and listen to some live music.

Employees like the perk. In the past, Stevie Wonder and Gwen Stefani have played Beer Bash.

But over the weekend, Apple may have outdone itself for Earth Day. It booked Ziggy Marley, reggae legend Bob Marley's son, to play at 1 Infinite Loop. 

The concert was to celebrate Earth Day and capped off a week of environmental announcements from the iPhone company, including that all Apple facilities now run off of renewable energy.

Ziggy noted the environmental connection - he said it was his first solar-powered concert - but it should also be noted that he's an outspoken cannabis advocate, and the concert took place on April 20, a sort of St. Patrick's Day for weed fans.

Recreational marijuana use is legal in California, and Apple doesn't drug test new hires for cannabis. (It's also worth noting that this concert took place at Apple's old headquarters, not the new $5 billion Apple Park "spaceship" campus, and smoking is banned on both campuses.)

Here's a clip of Ziggy playing an old Bob Marley tune on Friday:

Apple CEO Tim Cook is jamming!