In the broadest sense, contemporary music is any music being written in the present day. In the context of classical music the term applies to music written in the last half century or so, particularly works post-1960. The argument over whether the term applies to music in any style, or whether it applies only to composers writing avant garde music, or "modernist" music is a subject of hot debate. There is some use of "Contemporary" as a synonym for "Modern", particularly in academic settings, whereas others are more restrictive and apply the term only to presently living composers and their works. Since it is a word that describes a time frame, rather than a particular style or unifying idea, there are no universally agreed on criteria for making these distinctions.
Many contemporary composers working the early 21st century were prominent figures in the 20th century, including György Ligeti, Mauricio Kagel, Harrison Birtwistle, Elliot Carter, Steve Reich, Philip Glass, John Adams and Henri Dutilleux and many younger figures such as Oliver Knussen and Thomas Adès. For more examples see: List of 21st century classical composers.
There are a number of festivals dedicated to contemporary music, among them the Donaueschingen Festival of Contemporary Music and Huddersfield Contemporary Music Festival.
In the early part of the 20th century contemporary music included modernism. The twelve tone technique, atonality, unresolved and greater amounts of dissonance, rhythmic complexity and neoclassicism. In the '50s contemporary music generally meant serialism, in the '60s serialism, indeterminacy, electronic music including computer music, mixed media, performance art, and fluxus, and since then minimal music, post-minimalism, and all of the above.
Since the 1970s there has been increasing stylistic variety, with far too many schools to name or label. However, in general, there are three broad trends. The first is the continuation of modern avant garde traditions, including musical experimentalism, for example by Magnus Lindberg. The second are schools which sought to revitalize a tonal style based on previous common practice, including John Corigliano and John Rutter. The third focuses on non-functional triadic harmony, exemplified by composers working in the minimalist and related traditions.
Contemporary music composition has been altered with growing force by computers in composition, which allow for composers to listen to renderings of their scores before performance, compose by layering performed parts over each other as John Adams is known to do, and to disseminate scores over the internet. It is far too soon to tell what the final result of this wave of computerization will have as an effect on music.
All history is provisional, and contemporary history even more so, because of the well known problems of dissemination and social power. Who is "in" and who is "out" is often more important to who is known than the music itself. In an era with perhaps has many as 40,000 composers of concert music in the United States alone, first performances are difficult, and second performances even more so. The lesson of obscure composers in the past becoming important later applies doubly so to contemporary music, where it is likely that there are "firsts" before the officially listed first, and works which will be later admired as exemplars of style, which are as yet, unheralded in their own time.
Movements in contemporary music
Main article: Modernism (music)
Many of the key figures of the high modern movement are alive, or only recently deceased and there is also still an extremely active core of composers, performers and listeners who continue to advance the ideas and forms of Modernism. Elliot Carter is still active, for example, as is Lukas Foss. While high modernist schools of composing, such as serialism are no longer as rhetorically central, the contemporary period is beginning the process of sorting through the modern corpus, looking for works which will have repertory value.
Modernism is also present as surface or trope in works of a large range of composers, as atonality has lost much of its ability to terrorize listeners, and even film scores use sections of music clearly rooted in modernist musical language. Active modernist composers include Harrison Birtwistle, Alexander Goehr, Judith Weir, Thomas Ades, Magnus Lindberg and Gunther Schuller.
Main article: Postmodern music
Post-modernism is, naturally, a strong influence in contemporary classical music. One critic remarked that the easiest way to find "post-modernism" is to find the word "new" or the prefix "post-" attached to the name of a movement. However, in an era where media, systematic presentation, and power relationships remain the dominant reality for most people born in to the core industrialized nations, post-modernism is likely to remain the most common mode for artistic expression.
When Duchamp displayed a urinal in an art museum, he struck the most visible blow for artistic conceptualism. Music conceptualism found a champion in John Cage. A conceptualist work is an act whose musical importance draws from the frame, rather than the content of the work. An example would be Alvin Singleton's 56 Blows, a work that has the distinction of being mentioned in debate on the floor of the Senate.
Minimalism and post-minimalism
Main articles: Minimalist music, Post-minimalism
The minimalist generation still has a prominent role in new composition. Philip Glass has been expanding his symphony cycle, while John Adams' work In Memoriam to 9-11 won a Pulitzer Prize. Steve Reich has explored electronic opera and Terry Riley has been active in composing instrumental music. But beyond the minimalists themselves, the tropes of non-functional triadic harmony are now common place, even among composers who are not regarded as minimalists per se.
Many composers are expanding the resources of minimalist music to include rock and world instrumentation and rhythms, serialism, and many other techniques. Kyle Gann considers William Duckworth's Time Curve Preludes as the first "post-minimalism" piece, and labels John Adams as a "post-minimalist" composer, rather than as a minimalist. Gann defines "post-minimalism" as the search for greater harmonic and rhythmic complexity by composers such as Mikel Rouse and Glenn Branca. Post-minimalism is also  (http://www.guggenheimcollection.org/site/movement_works_Post_Minimalism_0.html) a movement in painting and sculpture which began in the late 1960s. (See lumpers/splitters)
Post classic tonality
Other aspects of post-modernity can be seen in a "post-classic" tonality that has advocates such as Michael Daugherty and Tan Dun.
With a wide range of styles in performance, many contemporary composers work by combining styles, a technique known as polystylism, or even multiple genres of music. One influential composer in this vein is John Zorn.
Main article: World music
An increasing number of composers mix western and non-western instruments, including gamelon from Indonesia, Chinese traditional instruments, ragas from Indian Classical music. There is also an exploration of non-Western tonalities, even in relatively traditionally structured works. This can be in the context of post-minimalist works, such as Janice Giteck's Balinese influenced works, or in the context of post-classic tonality, such as in the music of Bright Sheng, or in the context of thoroughly modernist styled works.
Main article: Experimental music
One important movement in contemporary music involves expanding the range of gestures available to instrumentalists, for example the work of George Crumb. The Kronos Quartet has been among the most active ensembles in promoting contemporary works for string quartet, and they take delight in music which stretches the manner in which sound can be drawn out of instruments.
Main article: Electronic music
Electronics are now part of mainstream music creation. Performances of regular works often use midi synthesizers to back or replace regular musicians. However the older idea of electronic music - as a search for pure sound and an interaction with the hardware itself - continues to find a place in composition, from commercially successful pieces to works targeted at very narrow audiences.
Main article: Neoromanticism (music)
The resurgence of the vocabulary of extended tonality which flourished in the first years of the 20th century continues in the contemporary period, though it is no longer considered shocking or controversial as such. Composers working in the neoromantic vein include George Rochberg and David Del Tredici.
"New Complexity" is a current within today's European contemporary avant-garde music scene. Among this diverse group are Richard Barrett, Brian Ferneyhough and Michael Finnissy. Another is spectral music, epitomized by the works of Tristan Murail, Gérard Grisey, and Claude Vivier.
- NewMusicBox.org: The Century List: 100 Reasons to Play This Century's Music (http://www.newmusicbox.org/archive/century/index.html) 20 Under 20-Minute Works by Living American Composers Ready to be Programmed Now compiled by Frank J. Oteri