echoing patates here just a bit:
Western Classical Composer: wouldn't know here
Western Classical Performer: Fazıl Say (heard of his name, but haven't heard any of his music yet)
Turkish Classical Composer: wouldn't know here
Turkish Classical Performer: wouldn't know here
Country Group: Laço Tayfa [agreed], Babazula
Country Solo Artist: Burhan Öçal, or Hüsnü Şenlendirici, or Selim Sesler
Turkish Blues (arabesk): Muslum Gures
Electronica: Orient Expressions, or Mercan Dede (cannot go wrong here, all are amazing)
Folk Group: Yansımalar [agreed]
Folk Solo Artist: Sabbahat Akkiraz (amazing voice)
Jazz Group: wouldn't know here
Jazz Solo Artist: wouldn't know here
Heavy Metal Group: Pentagram aka Merzarkabul [agreed], there is also Pinhani
Hip-hop/Rap Group: Cartel, King Size Terror, Karakan (these are the pioneers of turk hip hop)... and yes Nefret as well
Hip-hop/Rap Solo Artist: Sagopa Kajmer (aka Dj Mic Check, Silahsiz Kuvvet), Sultana, Aziza A, Kolera, Zet, Fuat (aka Fuat Ergin), Fuchs (aka Dr. Fuchs), Ayben, Ceza is ok, but has a more mainstream sound.
Movie Score Composer: wouldn't know here
Pop Group: Anima
Pop Female Solo Artist: Hande Yener, Sezen Aksu, Nil Karaibrahimgil
Pop Male Solo Artist: Tarkan [agreed], also Kenan Dogulu, Teoman, Murat Boz (tarkan wannabe lol)
Rock Group: Replikas, Fairuz Derin Bulut, Athena and yes, also Duman
Rock Solo Artist: Ozlem Tekin and yes also Şebnem Ferrah (they both were in a rock band together under the name Volvax)
Artist(s) that truly exemplify(ies) the heart of the Nation: Omar Faruk Tekbilek [agreed] (this guy has amazing music)
One to keep your eye on: Siyasiyabend street musicians featured on The Sound of Istanbul (music documentary of turkey), they are great...
* Notable mentions:
Barış Manço,
Kudsi Erguner
btw turkey is not my country, but i listen to things from around the world, thought i would add