In November 1986 Mark joined Vicious Rumors, a Bay Area metal band, as one of two guitarists and as harmony vocalist. Mark's distinctive melodic style and technical finesse became a key element in Vicious Rumors' signature sound. With VR, Mark recorded 4 studio albums (which he co-wrote and co-produced) and 2 live albums, performed in music videos that appeared on MTV, and toured the US, Canada, Mexico, Europe, Scandinavia, and Japan from 1987 to 1995 (23 countries).
In addition to playing a large role in Vicious Rumors' song writing and sound, Mark continued with his personal song writing. And at the beginning of 1995, after 9 years with VR, he notified the others in the band that he wished to go in a different direction and part ways, musically.