A demo version or demo of a song (shortened from the word "demonstration") is one recorded for reference rather than for release. A demo is a way for a musician to approximate their ideas on tape or disc, and provide an example of those ideas to record labels, producers or other artists. Musicians often use demos as quick sketches to share with bandmates or arrangers; in other cases a songwriter might make a demo to send to artists in hopes of having the song professionally recorded, or a music publisher may need a simple recording for publishing or copyright purposes.

Many unsigned bands and artists record demos in order to obtain a recording contract. These demos are usually sent to record labels in hopes that the artist will be signed onto the label's roster and allowed to record a full-length album in a professional recording studio. However, large record labels usually ignore unsolicited demos that are sent to them by mail; artists generally must be more creative about getting the demos into the hands of the people who make decisions for the record company.

Demo may refer to:

Music is an art form whose medium is sound and silence. Its common elements are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics, and the sonic qualities of timbre and texture. The word derives from Greek μουσική (mousike; "art of the Muses").

The creation, performance, significance, and even the definition of music vary according to culture and social context. Music ranges from strictly organized compositions (and their recreation in performance), through improvisational music to aleatoric forms. Music can be divided into genres and subgenres, although the dividing lines and relationships between music genres are often subtle, sometimes open to individual interpretation, and occasionally controversial. Within "the arts", music may be classified as a performing art, a fine art, and auditory art. There is also a strong connection between music and mathematics.

To many people in many cultures, music is an important part of their way of life. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound." Musicologist Jean-Jacques Nattiez summarizes the relativist, post-modern viewpoint: "The border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus ... By all accounts there is no single and intercultural universal concept defining what music might be."

Jordan Rudess (born Jordan Charles Rudes on November 4, 1956) is an American keyboardist best known as a member of the progressive metal band Dream Theater and the progressive rock supergroup Liquid Tension Experiment.

Rudess was born in 1956 into a Jewish family. He was recognized by his 2nd grade teacher for his piano playing and was immediately given professional tuition. At nine, he entered the Juilliard School of Music Pre-College Division for classical piano training, but by his late teens he had grown increasingly interested in synthesizers and progressive rock music. Against the counsel of his parents and tutors, he turned away from classical piano and tried his hand as a solo progressive rock keyboardist.

After performing in various projects during the 1980s, he gained international attention in 1994 when he was voted "Best New Talent" in the Keyboard Magazine readers' poll after the release of his Listen solo album. Two of the bands who took notice of Rudess were The Dixie Dregs and Dream Theater, both of whom invited him to join. Rudess chose the Dregs, primarily as being a part time member of the band would have less of an impact on his young family, a choice he was not given with Dream Theater.

Imogen Jennifer Jane Heap ( /ˈɪmədʒɨn ˈhiːp/; born 9 December 1977 in the London Borough of Havering) is a Grammy Award-winning English singer, composer and songwriter from Havering, Essex. She is known for her work as part of the musical duo Frou Frou and her solo albums, which she writes, produces, and mixes. She has produced three solo albums, the latest of which is 2009's Ellipse, which was a North American chart success and earned Heap two Grammy nominations, winning Best Engineered Album, Non-Classical.

For her solo work (as well as her work with Frou Frou and Acacia), Heap plays heavily produced and arranged singer-songwriter pop incorporating elements of rock, dance and electronica. As a guest player and collaborator she has played rock (Jeff Beck), hip-hop (Urban Species) and theatre/film music.

I just love crafting and shaping sounds. Actually, many of the sounds that I work with start off as organic instruments - guitar, piano, clarinet, etc. But I do love the rigidity of electronic drums... I would record live drums, and then I would spend a day editing them to take the life out of them. I like to breathe my own life into these sounds, and I do try to keep the 'air' in the music. Some people think electronic music is cold, but I think that has more to do with the people listening than the actual music itself.