Improvisation is the practice of acting, singing, talking and reacting, of making and creating, in the moment and in response to the stimulus of one's immediate environment and inner feelings. This can result in the invention of new thought patterns, new practices, new structures or symbols, and/or new ways to act. This invention cycle occurs most effectively when the practitioner has a thorough intuitive and technical understanding of the necessary skills and concerns within the improvised domain. Improvisation can be thought of as an "on the spot" or "off the cuff" spontaneous activity.

The skills of improvisation can apply to many different abilities or forms of communication and expression across all artistic, scientific, physical, cognitive, academic, and non-academic disciplines. For example, improvisation can make a significant contribution in music, dance, cooking, presenting a speech, sales, personal or romantic relationships, sports, flower arranging, martial arts, psychotherapy, and much more. Techniques of improvisation are widely trained in the entertainment arts; for example, music, theatre and dance. To "extemporize" or "ad lib" is basically the same as improvising. Colloquial terms such as "let's play it by the ear", "take it as it comes", and "make it up as we go along" are all used to describe "improvisation".

Keith Jarrett (born May 8, 1945, in Allentown, Pennsylvania) is an American pianist and composer who performs both jazz and classical music.

Jarrett started his career with Art Blakey, moving on to play with Charles Lloyd and Miles Davis. Since the early 1970s he has enjoyed a great deal of success in jazz, jazz fusion, and classical music; as a group leader and a solo performer. His improvisations draw not only from the traditions of jazz, but from other genres as well, especially Western classical music, gospel, blues, and ethnic folk music.

In 2003, Jarrett received the Polar Music Prize, the first (and to this day only) recipient not to share the prize with a co-recipient, and in 2004 he received the Léonie Sonning Music Prize.

In 2008, he was inducted into the Down Beat Hall of Fame in the magazine's 73rd Annual Readers' Poll.

Jarrett grew up in suburban Allentown, Pennsylvania, with significant early exposure to music. He possessed absolute pitch, and he displayed prodigious musical talents as a young child. He began piano lessons just before his third birthday, and at age five he appeared on a TV talent program hosted by the swing bandleader Paul Whiteman. The young Jarrett gave his first formal piano recital at the age of seven, playing works by composers including Mozart, Bach, Beethoven, and Saint-Saëns, and ending with two of his own compositions. Encouraged especially by his mother, Jarrett took intensive classical piano lessons with a series of teachers, including Eleanor Sokoloff of the Curtis Institute.

Robin McLaurin Williams (born July 21, 1951) is an American actor and comedian. Rising to fame with his role as the alien Mork in the TV series Mork & Mindy, and later stand-up comedy work, Williams has performed in many feature films since 1980. He won the Academy Award for Best Supporting Actor for his performance in the 1997 film Good Will Hunting. He has also won two Emmy Awards, four Golden Globes, two Screen Actors Guild Awards and five Grammy Awards.

Williams was born in Chicago, Illinois. His mother, Laura McLaurin (née Smith, 1922–2001), was a former model from New Orleans, Louisiana. His father, Robert Fitzgerald Williams (September 10, 1906 – October 18, 1987), was a senior executive at Ford Motor Company in charge of the Midwest region. His maternal great-great-grandfather was senator and Mississippi governor Anselm J. McLaurin. Williams is of English, Welsh, Irish, and French ancestry. He was raised in the Episcopal Church (his mother practiced Christian Science). He grew up in Bloomfield Hills, Michigan, where he was a student at the Detroit Country Day School, and later moved to Woodacre, Marin County, California, where he attended the public Redwood High School. Williams studied at Claremont McKenna College (then called Claremont Men's College) for four years. He has two half-brothers: Todd (who died August 14, 2007) and McLaurin.