Instrumental music relies on the dynamics of instrumentation instead of lyrics to get reactions and responses from the audience. In music that does include lyrics, but go vocally silent, these breaks are known as instrumental interludes. Some examples also have very small amounts of lyrics, just meant as a shock or to add value to the piece at selective times. “Tequila” is a popular example, where the entire song is instrumental, except for that one spoken word.
Instrumental music is sometimes likened to classical, but it is distinguished by style. Songs that do have lyrics have also had instrumental versions done for them, to give listeners a different take on a song they have already enjoyed. Instrumental versions are also done at times so that vocals can be laid over top, but the two parts be kept as different layers.