This is a synthesizer that combines a sophisticated drum machine with Hart's extensive library of sound samples.

[2][3] In Relix, Justin Jacobs wrote, "... on his latest solo release, RAMU, Hart's created a deliciously meandering, melodic exploration, with a whole cast of more contemporary voices adding some ecstatically fun spice to the global drum experience.

It’s like "Drums" and "Space" with an all-star backing band of internationals and aliens.... Thankfully, this 12-song collection is total, free-wheeling fun — all lunging rhythms, slithering jazz, bubbling beats, stacked vocals, and foggy atmospherics.

"[6] Pablo Gorondi of Associated Press said, "There's plenty of movement on Mickey Hart's 14th studio album, as the Grateful Dead drummer extends his prolific solo career centered on his amazing approaches to percussion, knowing expeditions into world music and the cross pollination between music and sciences.... the powers of RAMU stem from Hart's ability to calibrate layers upon layers of rhythms and melodies from bountiful sources — fine tuning instead of Auto-Tuning.

"[7] In a Rolling Stone interview of Hart, Andrew Leonard wrote, "Hart mixes the old – samples of blues recordings captured by Alan Lomax, snippets of never-before-heard Jerry Garcia guitar – with percussive, pulsating electronica.