A tessera (plural: tesserae, diminutive tessella) is an individual tile, usually formed in the shape of a cube, used in creating a mosaic. It is also known as an abaciscus or abaculus, and in Persian کاشي معرق.

In early antiquity, mosaics were formed from naturally formed colored pebbles, but by 200 BCE cut stone tesserae were being used in Ancient Roman decorative mosaic panels and floor mosaics. Marble or limestone were cut into small cubes and arranged into representational designs and geometric patterns.

Later, tesserae were made from colored glass, or clear glass backed with metal foils. The Byzantines used tesserae with gold leaf, in which case the glass pieces were flatter, with two glass pieces sandwiching the gold. This produced a golden reflection emanating from in between the tesserae as well as their front, causing a far richer and more luminous effect than even plain gold leaf would create.

These are manufactured glass tiles made to a uniform shape and size. They are made by molten glass being poured into trays and fired. An imprint of grooves is made on their underside for help with adhesion to cement when fixing.

Arthur Levering (born March 6, 1953, Baltimore, Maryland) is an American composer of contemporary classical music. He currently resides in Cambridge, Massachusetts and Rome, Italy.

Levering has received commissions from the Boston Modern Orchestra Project, Boston Musica Viva, the Dinosaur Annex Music Ensemble, the New Juilliard Ensemble, the Rascher Saxophone Quartet, and Sequitur, among others.

Levering holds a B.A. from Colby College (1976); an M.M. in performance from Yale University (1979), having studied classical guitar with Eliot Fisk; and an M.M. in composition from Boston University (1988), having studied primarily with Bernard Rands.

His virtuosic 3 movement piano work, School of Velocity, was commissioned and performed by Donald Berman on a League of Composers/ISCM concert at Merkin Hall, New York on March 23, 1999. Echoi (violin and piano) was premiered by Nicholas Kitchen and Donald Berman in Boston on Oct. 20, 2003. Clarion/Shadowing (clarinet, violin, piano) was performed by the 21st Century Consort at the Hirshhorn Museum in Washington, DC on March 13, 2004. Twenty Ways Upon the Bells (7 players) was premiered by Dinosaur Annex in Boston on Oct. 30, 1994. Cloches II (8 players) was performed by the Chamber Music Society of Lincoln Center on Feb. 15, 2001. Furies (11 players) was premiered by Sequitur at Merkin Hall in New York on Jan. 30, 2008. Catena (piano and 16 players) was premiered by Donald Berman and the Dinosaur Annex Chamber Orchestra, conducted by Scott Wheeler at Jordan Hall, Boston on Sept. 16, 2000. Parallel Universe (string orchestra) was performed and recorded by the Boston Modern Orchestra Project at Jordan Hall, Boston on May 25, 2007.

Herbert Jeffrey "Herbie" Hancock (born April 12, 1940) is an American pianist, keyboardist, bandleader and composer. As part of Miles Davis's Second Great Quintet, Hancock helped to redefine the role of a jazz rhythm section and was one of the primary architects of the "post-bop" sound. He was one of the first jazz musicians to embrace music synthesizers and funk music (characterized by syncopated drum beats). Hancock's music is often melodic and accessible; he has had many songs "cross over" and achieved success among pop audiences. His music embraces elements of funk and soul while adopting freer stylistic elements from jazz. In his jazz improvisation, he possesses a unique creative blend of jazz, blues, and modern classical music, with harmonic stylings much like the styles of Claude Debussy and Maurice Ravel.

Hancock's best-known solo works include "Cantaloupe Island", "Watermelon Man" (later performed by dozens of musicians, including bandleader Mongo Santamaría), "Maiden Voyage", "Chameleon", and the singles "I Thought It Was You" and "Rockit". His 2007 tribute album River: The Joni Letters won the 2008 Grammy Award for Album of the Year, only the second jazz album ever to win the award after Getz/Gilberto in 1965.