Given the question: Information: - A drumstick is a type of percussion mallet used particularly for playing snare drum, drum kit and some other percussion instruments, and particularly for playing unpitched percussion. - A drumhead or drum skin is a membrane stretched over one or both of the open ends of a drum. The drumhead is struck with sticks, mallets, or hands, so that it vibrates and the sound resonates through the drum. - A drum kitalso called a drum set, trap set, or simply drumsis a collection of drums and other percussion instruments, typically cymbals, which are set up on stands to be played by a single player with drumsticks held in both hands and the feet operating pedals that control the hi-hat cymbal and the beater for the bass drum. A drum kit consists of a mix of drums (categorized classically as membranophones, Hornbostel-Sachs high-level classification 2) and idiophones most significantly cymbals but also including the woodblock and cowbell (classified as Hornbostel-Sachs high-level classification 1). In the 2000s, some kits also include electronic instruments (Hornbostel-Sachs classification 53) and both hybrid and entirely electronic kits are used. A standard modern kit (for a right-handed player), as used in popular music and taught in music schools, contains: - The drum is a member of the percussion group of musical instruments. In the Hornbostel-Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a shell and struck, either directly with the player's hands, or with a drum stick, to produce sound. There is usually a "resonance head" on the underside of the drum, typically tuned to a slightly lower pitch than the top drumhead. Other techniques have been used to cause drums to make sound, such as the thumb roll. Drums are the world's oldest and most ubiquitous musical instruments, and the basic design has remained virtually unchanged for thousands of years. - A hi-hat, also spelled hihat or high-hat, is a combination of two cymbals, a foot-operated pedal which moves a rod which in turn moves one of the cymbals, all mounted on a metal stand. Hihats are an essential part of the standard drum kit used by drummers in many popular music (eg., every genre of rock music) and traditional music (e.g., blues) styles. It consists of a mating pair of small to medium-sized cymbals mounted on a stand, with the two cymbals facing each other. The bottom cymbal is fixed and the top is mounted on a rod which moves the top cymbal towards the bottom one when a foot pedal is depressed (a hihat that is in this position is said to be "closed" or "closed hihats"). - In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a transmission medium such as air or water. In physiology and psychology, sound is the "reception" of such waves and their "perception" by the brain. Humans can hear sound waves with frequencies between about 20Hz and 20kHz. Sound above 20kHz is ultrasound and below 20Hz is infrasound. Other animals have different hearing ranges. - A cymbal is a common percussion instrument. Often used in pairs, cymbals consist of thin, normally round plates of various alloys. The majority of cymbals are of indefinite pitch, although small disc-shaped cymbals based on ancient designs sound a definite note (see: crotales). Cymbals are used in many ensembles ranging from the orchestra, percussion ensembles, jazz bands, heavy metal bands, and marching groups. Drum kits usually incorporate at least a crash, ride or crash/ride, and a pair of hi-hat cymbals. A player of cymbals is known as a cymbalist. - A bass drum is a large drum that produces a note of low definite or indefinite pitch. - A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater (including attached or enclosed beaters or rattles); struck, scraped or rubbed by hand; or struck against another similar instrument. The percussion family is believed to include the oldest musical instruments, following the human voice. - Michael Colgrass (born April 22, 1932, in Chicago, Illinois) is an American-born Canadian musician, composer, and educator. - Popular music is music with wide appeal that is typically distributed to large audiences through the music industry. These forms and styles can be enjoyed and performed by people with little or no musical training. It stands in contrast to both art music and traditional or "folk" music. Art music was historically disseminated through the performances of written music, although since the beginning of the recording industry, it is also disseminated through recordings. Traditional music forms such as early blues songs or hymns were passed along orally, or to smaller, local audiences. - Rototoms are a drum developed by Al Payson and Michael Colgrass , that have no shell and are tuned by rotating . They consist of a single head in a die - cast zinc or aluminum frame . Unlike most other drums , they have a variable definite pitch . Composers are known to write for them as tuned instruments , demanding specific pitches . Rototoms are often used to extend the tom range of a standard drum kit . They were commercialized by the drumhead company Remo . Given the information, choose the subject and object entities that have the relation of 'subclass of'.
The answer is:
rototom , percussion instrument