Complex sentence: Bijelo dugme was founded by Goran Bregović who was born in Sarajevo, who spent much of his childhood in music school, studying violin, from which he was expelled for "lack of talent".
Split into simpler sentences: Bijelo Dugme was founded by Goran Bregović who was born in Sarajevo. He spent much of his childhood in music school, studying violin, but he was expelled for "lack of talent".