The second half of SOAD's album-in-two-parts is heavier, darker and less accessible than its previously released counterpart, Mezmerize. Though not as immediately catchy, it's easily the stronger of the two. Vocalist Serj Tankian and guitarist Daron Malakian harmonize beautifully, easily trading verses to give both singers equal time behind the mic. The songs here are more complex than the Mezmerize material -- album centrepiece Holy Mountains morphs from sludgy dirge to sweeping orchestral chorus in barely an instant. Aside from the ill-conceived power ballad Lonely Day, Hypnotize illustrates why System is one of the most compelling contemporary metal bands around today.