Nu-disco is a 21st-century dance music genre associated with a renewed interest in 1970s US disco as well as synthesizer-heavy 1980s European dance music styles. The genre was especially popular in the mid 2000s, and experienced another small resurgence in the early to mid 2010s.
French house could be considered the precursor of the movement in the late 1990s.
The moniker first appeared in print as early as 2002, and by mid-2008, used by record shops such as the online retailers Juno and Beatport. Originally, they associated it with re-edits of classic disco records and a handful of European electronic producers who made music in that style. It is also used by Beatport, alongside alternative dance, to describe the music on several American labels that were previously associated with the genres electroclash and french house.
In 2002, The Independent described nu-disco as the result of applying "modern technology and pin-sharp production" to ?70s disco and funk. In 2008, Beatport described nu-disco as "everything that springs from the late 1970s and early 1980s (electronic) disco, boogie, cosmic, Balearic and Italo disco continuum.Spin magazine placed an umlaut over the "u" in "nu", used the term interchangeably with Eurodisco, and cited strong Italo dance as well as electroclash influences, while many other labels refer to it as "Nu Disco," sans the hyphen. As of 2015, remixes and disco edits of old songs sit side-by-side with highly original productions on websites such as Beatport and Traxsource.
In the mid 2000s many covers and remixes of songs from the 1980s in the nu-disco style were popular as well as original songs in this style, with disco house songs such as "Lola's Theme" by the Shapeshifters, "Call on Me" by Eric Prydz, "The Weekend" by Michael Gray, "Out of Touch" by Uniting Nations, "Shine" by Lovefreekz, "So Much Love to Give" by the Freeloaders and two remixes of 1980s disco song "Waiting for a Star to Fall" all making the top ten of the UK Singles Chart in the second half of 2004 and first half of 2005. The trend continued until mid 2006, when more electronic varieties of house such as electro house began to become more popular.
In 2013, several disco and funk-influences songs charted as top hits, this time more in a 1970s style and one source stated that the pop charts had more dance songs than at any other point since the late 1970s. The biggest disco-house hit of the year as of June was "Get Lucky" by Daft Punk, featuring Nile Rodgers on guitar. The song was initially thought likely to be a leading candidate to become the summer's biggest hit that year; however, the song ended up peaking at number 2 on the Billboard Hot 100 chart for five weeks behind another major disco-styled song, Robin Thicke's "Blurred Lines", which spent twelve weeks at number 1 on the Hot 100, and in the process became the eventual song of the summer itself. Both were popular with a wide variety of demographic groups. Although many credit Daft Punk with bringing back disco in 2013, it is far from their most quintessentially French Disco record, and some even say that disco never left in the first place. But with high-profile collaborations with disco legends such as Giorgio Moroder and the aforementioned Nile Rodgers, disco is now not only in the public's ear, but in their consciousness as well.
A modified version of the original master, edited by disco and house DJs to extend and emphasize the best and most dance-friendly elements. Todd Terje's edit of the Bee Gees hit "You Should Be Dancing" does exactly that, downplaying the dated vocal riffs in favor of driving bass, lively percussion, and an overall sense of space. Many nu-disco producers are also disco editors and often there is a bit of overlap between the two genres as many nu-disco songs feature samples of classic disco tracks. It is also not uncommon for an edit to be made of a modern track.
Since nu-disco is a dance genre first and foremost, the drum grooves are an essential part. They often feature four-on-the-floor beats with an organic, lively feel based on the sounds of classic disco recordings by Chic, Sister Sledge, and others. In some cases, producers will sample these grooves directly. Los Angeles-based producer Goldroom uses both house and disco influenced drum grooves in tracks such as "Waiting to Ignite"
While modern production is abundant with synthesized sounds, many nu-disco records are, in the disco tradition, driven by guitar or bass licks. Guitarist, producer, and songwriter Nile Rodgers brought riffs to the forefront of the groove with Chic in the 1970s and again with Daft Punk in 2013. Other notable modern examples include "Baby I'm Yours" by Breakbot and "Holding On" by Classixx
As with other electronic genres, nu-disco producers use both digital and analog synths to create melodic and harmonic lines, and add ambiance and color to their records. Gigamesh uses a heavily synthesized sound while still retaining old-school influences in tracks such as "Back To Life", and Poolside uses atmospheric synths to compliment their drum, bass, and guitar sounds in "Do you Believe" 
Unlike its disco precursors, nu-disco and disco house are not beholden to song forms that are essential to the modern pop idiom. Rather than following the traditional verse-chorus model, nu-disco tends to take after its electronic cousins, with more drawn-out, repetitive sections that slowly ramp up to the chorus and back down again. Otherwise monotonous lines are brought to life with the use of filters, samples, and other subtle changes in the sound or groove over time in ways that make people want to keep dancing. Daft Punk 's "One More Time" is considered one of the most influential examples of the application of "filter disco." 
Black Cock Records (UK) Founded by DJ Harvey and operating primarily in the 1990s, Black Cock was one of the go-to labels for disco mixes and re-edits, and encouraged many young DJs to incorporate disco elements into their house mixes, despite it being out of fashion at the time.
Nuphonic Records (UK) Known as a mark of quality for any number of electronic genres and subgenres, Nuphonic Records help launch a number of important acts in the 1990s and early 2000s such as Faze Action and Raj Gupta, and was one of the early pioneers of collaboration, fusion of genres, and live performance in disco house and beyond. Some attribute their name to having influenced the creation of the nu-disco moniker.
DFA Records (NYC) DFA Records was initially started by James Murphy (electronic musician) as a platform to launch his and his band's music.While he is best known for his work with LCD Soundsystem, the label has played host to many iconic dance rock and nu-disco acts, including its very first hit with The Rapture and, more recently, nu-disco/ electronica project The Juan MacLean.
Roche Musique (FR) In the past three years, progressive nu-disco and chill electronica label Roche Musique has been throwing parties and churning out hits on the French scene. While they do not subscribe to a particular genre label, their style is equally rooted in tradition as it is forward-thinking. Citing the importance of the "French Touch", artists such as FKJ and Darius create precise and memorable productions with a variety of influences, which are now just beginning to get noticed worldwide.
Ballroom Records (US) Now defunct label that produced a large number of bootleg re-edits released as white labels.
This French duo has had a significant influence on nu-disco and numerous genres related to it. From their unique reinterpretations of classic disco records on Homework and Discovery to their Nile Rodgers-driven super hit "Get Lucky" to side projects such as Thomas Bangalter's Stardust, the name Daft Punk is synonymous with the French house music scene and innovations in the nu-disco space. While countless Frenchmen have contributed to the distinctly French elements of nu-disco, Daft Punk takes most of the credit for bringing that style to America and into the mainstream.
Another major figure on the French scene, Dimitri from Paris is in many ways responsible for more of the nu-disco scene than any other individual in the business. Rather than focusing on quintessential 1970s pop records, he draws inspiration from more esoteric sources such as 1950s jazz, Latin exotica, and film soundtracks.
Hailing from Norway, Hans-Peter Lindstrøm pioneered a new sound in the clubs of Europe that would become a precursor to nu-disco. With a musical background spanning from country and rock to gospel and jazz, Lindstrom's "Norse House" brought all the style and substance of classic 1970s jams to the modern dance floor, without the expense or the kitsch. Equally important are some of his peers, such as studio mate Prins Thomas and protege Todd Terje. Although the Norwegians' approach to nu-disco is distinct and hardly all-encompassing, elements of it can be heard in clubs and basements from London to Los Angeles.
Beatport is launching a new landing page, dedicated solely to the genres of "nu disco" and "indie dance". ... Nu Disco is everything that springs from the late ?70s and early ?80s (electronic) disco, boogie, cosmic, Balearic and Italo disco continuum...[dead link]