Tibetan singing bowls are used for religious purposes, music making and meditation, as well as for relaxation and personal well-being. They have become popular with music therapists and sound healers, yoga and meditation practitioners.
In the West, Tibetan singing bowls are sometimes used in alternative medicine, their modern popularity for that purpose perhaps deriving from the modal vibration studies known as Cymatics carried out by the physician Hans Jenny (1904–1972). They are also used in sound therapy and for personal spirituality by work on the chakras. Western recordings of Tibetan music frequently associate the bowls with relaxation, as well as attributing them with healing powers and the ability to create an altered state in the mind of the listener.
Musically, these objects are classified as a type of bell (a bell is a hollow object which has maximum vibration around an open rim. A gong on the other hand has maximum vibration towards the centre). They are usually placed on a pillow, to allow the rim to vibrate freely, though small bells may be held gently in the hand.
They are often played by striking, in which case they sound a bell note as a struck idiophone.
Alternatively, some bells may be capable of 'singing bowl' operation as a friction idiophone. In this mode, a wooden mallet sometimes called a wand or puja is rotated around the outside rim to excite continuous vibrations in the bowl by the slip-stick mechanism, the principle being the same as that of water-tuned musical glasses. The volume of the continuous note depends on the speed of the mallet and the force that is applied.
Singing bowls may be partly filled with water, allowing them to be tuned. A Chinese form known as a spouting bowl has handles which, when rubbed with damp hands, causes water droplets to leap up as a result of standing waves known as Chladni patterns on the water surface. Such bowls are said to have been manufactured from as early as the 5th century BCE.
In the religious context, Tibetan Singing Bowls are primarily associated with Buddhist meditation and chanting, although they are also used in Taoist practices.
Vibrational Behaviour Studies
The vibrational behaviour of bowls has been simulated and has been widely studied, both under friction-induced puja excitation and also after being struck. In the former case, experiments indicate that bowls exhibit both radial and tangential motion, in concurrent stable and unstable modes. The unstable mode rotates around the bowl at the same angular velocity as the puja, resulting in beating phenomena always being heard, even with a perfectly symmetrical bowl. Rattling or chattering may occur, particularly with harder puja, lower contact forces and greater angular velocity. Research has also been carried out using loudspeaker-induced oscillation. Studies have investigated the behaviour of bowls partly filled with water, the way in which the resonant response varies with temperature, and the characteristics of drop-ejection from the liquid surface.
Use In Music
Bowls that were capable of singing began to be imported to the West from around the early 1970s. The musicians Henry Wolff and Nancy Hennings have been credited with the singing bowl's introduction for musical purposes in their 1972 new-age album Tibetan Bells (although they gave no details of the bowls used in the recording). This was the first in what would become a series of five related releases: Tibetan Bells II (1978), Yamantaka with Mickey Hart (1982), Tibetan Bells III (1988), and Tibetan Bells IV (1991). The albums are based on the concept of taking a spiritual journey, with the music as a guide.
Wolff and Hennings' seminal recording was followed by the development of a unique style of American singing bowl music called 'Tibetan music'. This has remained very popular in the US with many recordings being marketed as World music or New-age music since the introduction of those terms in the 1980s. Tibetan singing bowls have as a result become a prominent visual and musical symbol of Tibet, to the extent that the most prevalent modern representation of Tibet within the US is that of bowls played by Americans.
Singing Bowls are called for in several contemporary classical music scores, including Philipe Leroux's Les Uns (2001); John Cage / Lou Harrison's Double Music (1941); Messiaen's Oiseaux exotiques (1955/6); Taverner's Total Eclipse (1999); Tan Dun Opera's Marco Polo (1995); and Joyce Bee Tuan Koh's Lè (1997). In Japan they are also used in Kabuki theatre.
Longplayer is a musical composition for Tibetan bells by Jem Finer. Six recorded selections from a short piece of source music play simultaneously, at different pitches and speeds, combined such that no combination is repeated until one thousand years has elapsed.