US power metal (often abbreviated USPM) is often faster than standard heavy metal, with a more riff-driven approach than its later European counterpart, but more melodic and often with a higher emphasis on guitar leads than thrash metal. USPM is also notable for its wide (but not universal) use of high-register operatic vocals, a trend which would continue with the birth of European power in the late 80s/early 90s. A notable difference between the American and European styles is the use of keyboards; While almost universal in the European style, they are fairly rare in the American style.