Freestyle music, a subgenre of electronic dance music that emerged in New York City in the 1980s, has resurfaced in rap thanks to SOB X RBE and ShittyBoyz.

The midpoint of Teejayx6‘s breakout mixtape The Swipe Lessons is a song titled “Evidence.” The track starts off with a sample of The S.O.S. Band’s “High Hopes.” Slap bass fuses with skittering hi-hats from producer Undefined, transforming the instrumental into what sounds like a freestyle beat. Some of the characteristics of freestyle music — a subgenre of electronic dance music that emerged in New York City in the 1980s — are there: an upbeat dance tempo and syncopated bass line, and sixteenth-note hi-hats. And although “High Hopes” isn’t a freestyle song, the genre it’s classified as — boogie — is one of several that helped birth freestyle.

In an age of bouncy and slow trap-based rap music — where the tempos of songs are usually between 130 and 160 beats per minute (BPM) — it’s refreshing that certain rappers are bringing freestyle music into the present by rapping over some of the subgenre’s classics, or over beats that feel and sound like freestyle. And that this is primarily occurring in the Bay Area and Detroit — who share a long-lasting kinship as it pertains to rap — is not a surprise, considering how popular freestyle music was, throughout the late ’80s and early ’90s, in both areas.

There are two songs that are often credited as the foundation for freestyle music: Afrika Bambaataa’s “Planet Rock” and Shannon’s “Let the Music Play.” Not only were both tracks representative of the Black and Latinx teens and young adults the music primarily catered to — the Puerto Rican-born Chris Barbosa produced and wrote “Let the Music Play;”freestyle music has also been referred to as “Latin freestyle” because many of subgenre’s artists were Latinx — but they provided the blueprint for the freestyle tracks that succeeded them. Where the former was one of the first hit singles to use the Roland TR-808, the latter explored the drum machine’s capabilities even further and incorporated Latin-American rhythms, particularly the robotic claves (a percussion instrument featured prominently in Cuban music) heard throughout the song.

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“We went to 130 beats per minute, and from that came Latin freestyle, Miami bass and all that,” Bambaataa said of “Planet Rock” back in 2009.

Freestyle continued to grow in New York City thanks to the likes of Lisa Lisa and Cult Jam, Lil Suzy, The Cover Girls, and others. Freestyle scenes were beginning to pop up elsewhere throughout the country, too. Miami’s Debbie Deb, Company B, Exposé, and Stevie B; the Bay Area’s Jocelyn Enriquez, Buffy, Jaya, and M:G; and Philadelphia’s Pretty Poison. The late ’80s and early ’90s is when the subgenre peaked, with freestyle artists signing with major labels like Columbia and Virgin, as well as embarking on arena tours.

“The late ’80s we were touring the country,” George Lamond, a freestyle artist best known for his song “Bad of the Heart,” told Red Bull in 2015. “They booked arenas from west to east. We actually had six tour buses.”

Freestyle’s popularity came to an end around ’93 or ’94. Not only was the genre oversaturated with vocalists but it was being eclipsed by other types of dance music, as well as New Jack Swing and rap.

“All the major labels thought freestyle was like the next hip-hop, so they started signing all these groups: Sa-Fire, Cover Girls, Coro, Exposé, Stevie B, Sweet Sensation,” Sal Abbatiello, a music executive and the creator of The Cover Girls, told Red Bull. “Except what happened was they didn’t know what to do with them. They were trying to change their sound to pop.”

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Louis “Kayel” Sharpe, a member of the New York City freestyle trio TKA, also spoke on the quality of the music being released as a result of that oversaturation, saying: