Like the eastern flat-based lyre, the western round-based lyre also had several sub-types. Homer described two different western lyres in his writings, the phorminx and kitharis. However, both of these terms have not had uniform meaning across time, and their use during Homer's time was later altered. Today, scholars divide instruments referred to as kitharis into two subgroups, the round-based cylinder kithara and the flat-based concert kithara.
lIke The EaStErn flat-bAsed lYre, thE westerN roUnd-basEd lYre alsO hAd seVERal sUB-TyPes. hOmer descriBEd Two diFfErent WEsTern LYres iN hIS wRItingS, tHe phOrmInx AnD KithArIs. HowevEr, both of thesE terMS haVe not HAd uNiforM MEaniNg acRoSs tIMe, anD theIR uSe dURing homer'S TIme wAs Later aLtEred. todAY, schoLaRS divide iNSTruMEnts referred tO AS KItharis INto tWo SUbGrOuPs, thE rOUnd-Based cylInder kIthara ANd the fLaT-baSeD concert kithArA.