House is uptempo music for dancing, although by modern dance music standards it is mid-tempo, generally ranging between 118 and 135 bpm. Tempos were slower in house's early years. The common element of house is a prominent kick drum on every beat (also known as a four-on-the-floor beat), usually generated by a drum machine or sampler. The kick drum sound is augmented by various kick fills and extended dropouts. The drum track is filled out with hi-hat cymbal patterns that nearly always include an open hi-hat on eighth note off-beats between each kick, and a snare drum or clap sound on beats two and four of every bar. This pattern is derived from so-called "four-on-the-floor" dance drumbeats of the 1960s and especially the 1970s disco drummers. Producers commonly layer sampled drum sounds to achieve a more complex sound, and they tailor the mix for large club sound systems, de-emphasizing lower mid-range frequencies (where the fundamental frequencies of the human voice and other instruments lie) in favor of bass and hi-hats.