In February, String Cheese Incident drummer Jason Hann reported via Facebook that he was in the studio with The Grateful Dead’s Mickey Hart recording a new album produced by Michal Menert. In the post, he noted he laid down “15 tracks of drums and some electronic overdubs in a 24 hr period.” He also says that he got to hear recordings on the album from Zakir Hussain, Sikiru Adepoju, and Giovanni Hidalgo, all of whom are featured on Planet Drum and many other projects with Hart. The project has been more or less under wraps, with no set release date announced.

However, today, we’re getting more clues about this mysterious project. Dead & Co’s bassist Oteil Burbridge just posted via Instagram that he’s really making the most of his time on the West Coast for his San Francisco Bicycle Day performance yesterday. In the post wishing fans a happy 4/20, he posted a picture of him in the studio alongside Mickey’s drum kit and noted “I got to record on a new @mickeyhart record the first day,” before detailing the other moments of his trip. You can check out the post for yourself below, and stay tuned for more news about Mickey Hart’s new album as it’s revealed.