His story is told in fly-on-wall film Los Wild Ones, premiered at this year's SXSW film festival in Austin.
Directed by Elise Solomon, the movie captures the 52-year-old in his fatherly role to his roster of 23 acts of mainly Hispanic musicians who write and perform 50s rock'n'roll.
But one of his closet friends is Irish singer Imelda May who paid tribute to him as one of the first people who encouraged her to sing, during a One Night Only special with Gay Byrne last year.
Imelda told the Herald: "Reb is one of my closest and dearest friends. A very creative man, he continues to fly the flag for the music he loves with extreme passion."
The label boss was also directly involved in introducing her to her future husband Darrell who added:
"I met Imelda at Reb's flat in Tufnell Park, London 16 years ago. I spent the weekend trying to impress her and eventually we both sat outside on Reb's front doorstep watching the sun come up."
The couple, who later married, hang out with Reb each time they visit the US and Reb was one of the first people they told when Imelda got pregnant with their first child.
Speaking ahead of an Irish screening for Los Wild Ones, Reb revealed how being the boss of a trendy label has led to him meeting many of his heroes, including hell raiser Lemmy from Motorhead.
Los Wild Ones, which won Best Feature Documentary at the Phoenix Film festival and a string of rave reviews, will be released across Europe next month.