Carlos Santana is reportedly ‘doing well’ under hospital observation after collapsing onstage during a concert in Michigan overnight.

The guitar legend was mid-gig at the Pine Knob Music Theater when the scary moment unfolded.

A concertgoer told TMZ Santana was “about four or five songs into his set” when he realised something was wrong.

Santana reportedly sat down in front of the drums before collapsing backward. Staff and medical first responders rushed to his aid.

TMZ reported a black tarp was brought out to shield Santana while officials worked on him.

A rep said the 75-year-old’s medical episode was brought on by heat exhaustion and dehydration.