Drums with cylindrical shells can be open at one end (as is the case with timbales), or can have two drum heads, one head on each end. Single-headed drums typically consist of a skin stretched over an enclosed space, or over one of the ends of a hollow vessel. Drums with two heads covering both ends of a cylindrical shell often have a small hole somewhat halfway between the two heads; the shell forms a resonating chamber for the resulting sound. Exceptions include the African slit drum, also known as a log drum as it is made from a hollowed-out tree trunk, and the Caribbean steel drum, made from a metal barrel. Drums with two heads can also have a set of wires, called snares, held across the bottom head, top head, or both heads, hence the name snare drum. On some drums with two heads, a hole or bass reflex port may be cut or installed onto one head, as with some 2010s era bass drums in rock music.
Among digital pianos, there are several differences. The three main types of digital pianos are standard digital pianos, upright digital pianos, and stage pianos. Upright vertical pianos are built with a large cabinet, not unlike a real upright piano. They are often fitted with the best hammer action key systems and tone generation engines so that they are comparable to real upright pianos. Obviously, they still take up as much space as a real one, but there is less maintenance required. Stage pianos are digital pianos designed to be used in live performances, or on stage. They are much more portable than traditional pianos, and much sturdier than standard digital pianos. Standard digital pianos are intended more for practice and play at home. They are not as large or fully featured but offer an excellent balance of sound and portability.
Just like the acoustic instruments they're derived from, digital pianos come in different sizes. They also offer dozens of options for your perusal, so you can weigh all kinds of factors to find the right model for you. For instance, if you're looking to pack a lot of piano into as small a space as possible, consider instruments such as the Williams Allegro 88-Key Digital Piano or the Casio CDP-120. These are fairly compact pianos, but that doesn't limit the breadth of their samples and sound settings.
Palm-muting is a widely used bass technique. The outer edge of the palm of the picking hand is rested on the bridge while picking, and "mutes" the strings, shortening the sustain time. The harder the palm presses, or the more string area that is contacted by the palm, the shorter the string's sustain. The sustain of the picked note can be varied for each note or phrase. The shorter sustain of a muted note on an electric bass can be used to imitate the shorter sustain and character of an upright bass. Palm-muting is commonly done while using a pick, but can also be done without a pick, as when doing down-strokes with the thumb.
Another common form is the stage piano, designed for use with live performances, professional audio, or in recording studio. This type of digital piano normally makes no attempt to imitate the physical appearance of an acoustic piano, rather resembling a generic synthesizer or music workstation. A distinguishing feature of most stage pianos is a lack of internal loudspeakers and amplification - it is normally assumed that a powerful keyboard amplifier or PA system will be used. However, some stage pianos are equipped with powered speakers.
A drum kit — also called a drum set, trap set (a term using a contraction of the word, “contraption”), or simply drums — is 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 can also include 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). Also, both hybrid (mixing acoustic instruments and electronic drums) and entirely electronic kits are used.
A three-piece drum set is the most basic set. A conventional three-piece kit consists of a bass drum, a 14" diameter snare drum, 12"–14" hi-hats, a single 12" diameter hanging tom, 8"–9" in depth, and a suspended cymbal, in the range of 14"–18", both mounted on the bass drum. These kits were common in the 1950s and 1960s and are still used in the 2010s in small acoustic dance bands. It is a common configuration for kits sold through mail order, and, with smaller sized drums and cymbals, for kits for children.