Marcelo Silva Barbosa, born on April 7, 1975, is a renowned Brazilian guitarist and music teacher known for his contributions to the power metal, speed metal, and progressive metal genres. He is a member of the bands Angra, Khallice, and Almah. Barbosa began playing the electric guitar at the age of 11 and became a professional musician and music teacher by 17. He founded the GTR music school in Brasília, where he developed his own teaching approach and materials.

Throughout his career, Barbosa has studied with various prominent musicians and attended workshops and classes, including summer courses at the Berklee College of Music, where he was offered a scholarship. He initially played with the Brasília pop rock band Zero10 before focusing on progressive metal with Khallice.

In 2007, Barbosa joined Almah, a band formed by members of Angra, and participated in national tours and the recording of the album "Fragile Equality." In September 2015, he joined Angra, replacing Kiko Loureiro. Barbosa is also a columnist for several guitar magazines in Brazil and has authored a book on guitar techniques. He is endorsed by Ibanez, Elixir Strings, Nig pedals, and Ibox.