Hardcore can refer to several musical genres:

• Hardcore Punk: musical style derived from Punk Rock that, in synthesis, radicalizes it through an emphasis on the angry and fast of both the lyrics and the music itself.
• Hardcore Hip Hop: musical style derived from Boom Bap; its mainstay is aggressive and angry vocals coupled with violent and somber lyrics, usually dealing with life in the ghettos and/or gangs.
• New York Hardcore: musical style derived from Hardcore Punk; at first it was a subgenre influenced by styles such as Oi! and Trashcore, but in the nineties it became a subgenre more influenced by Metalcore, Crossover Trash and Groove Metal. The lyrics tend to deal with themes linked to the working class and brotherhood, especially within the New York scene.
• Metalcore: musical style that derives from a mixture of several genres; Hardcore Punk, New York Hardcore, Crossover Trash, Trash Metal and Groove Metal. Its base is the breakdowns; extremely heavy and rhythmic sections that signify the peak of the aggressiveness in the song.
• Mathcore: musical style derived from Metalcore; it is a subgenre characterized by its rhythmic complexity and sound experimentation.
• Deathcore: musical style that derives from Metalcore; it is a mix between the breakdowns and the use of palm mute of Metalcore with the aggressiveness and blast beats of Death Metal. Generally, there is a tussle between slow and aggressive sections.
• Gabber: musical style that derives from Rave and means a more aggressive version of it; it emphasizes the use of a distorted bass drum and tempos between 180 and 300 beats per minute.
• Nu Style Gabber: musical style derived from Gabber; the difference lies in the fact that the drums are even more dense and distorted and the speed is reduced, concentrating on approximately 160 beats per minute.

In itself, the term hardcore, musically speaking, refers to fast and aggressive genres.