Heavy riffs are powerful, distorted guitar phrases commonly found in genres like heavy metal, hard rock, and punk. They often feature low, aggressive tones that create a strong rhythmic foundation for a song. These riffs are typically played with techniques such as palm muting and power chords, contributing to their intense sound. The use of heavy riffs can evoke strong emotions and energize listeners, making them a staple in live performances. Bands like Black Sabbath and Metallica are known for their iconic heavy riffs, which have influenced countless musicians and shaped the landscape of modern rock music.