When Ski Mask the Slump God discussed the genre's lo-fi sound and recording techniques, he noted, 'It was like the worst recording set up, you could set it up anywhere and that was the wave we were on. Todd Moscowitz, the founder of Alamo Records, called the scene a ' lo-fi movement' noting the heavily distorted bass and intentional lack of polish in the sound. In 2017, music critic Jon Caramanica of The New York Times opined that SoundCloud rap 'in the last year has become the most vital and disruptive new movement in hip-hop'. Smith writes that 21 Savage unfairly gets classified as a mumble rapper. There is also conflation between mumble/SoundCloud rap and other new generation-led evolutions or niches such as trap and cloud rap. There are disputes as to whether some rappers are mumble rappers or not.

He wrote that many of the artists often scapegoated in conversations about the subgenre do not actually mumble, which 'is the red flag that the term isn't a useful subcategorization.'

Justin Charity, a staff writer at The Ringer, argues that the term is unnecessarily reductive and does not in fact refer to one specific type of rapping. Oscar Harold of the Cardinal Times stated that 'mumble rap' is misleading, arguing that the rappers such as Future rely more upon pop melodies and vocal effects, such as Auto-Tune, than mumbling. 'Mumble rap' is nearly exclusively used as a derogatory term in reference to a perceived incoherence of the artist's lyrics. Rappers labelled as 'mumble rappers' also tend to use the 'aye' flow, where they add words such as 'yeah', 'aye' and 'uh' to the start or end of their lines. 'Mumble rappers' tend to talk about drugs, sex, money, jewelry, designer clothing, and partying. Some have claimed that artists such as Das EFX and Fu-Schnickens rapped in a similar style years before the term was created.

The term was first used to describe rappers whose lyrics were unclear, but the use of the term has expanded to include rappers that Reddit posters and YouTube commenters claim generally put little emphasis on lyricism or lyrical quality. There is disagreement over who first rapped in such a style, although its creation has been attributed to rappers such as Gucci Mane, Chief Keef, and most notably Future, whose 2011 single ' Tony Montana' is often cited as the first mumble rap song. The term 'mumble rap' was first used in 2014 by VladTV battle rap journalist Michael Hughes, in an interview with battle rapper Loaded Lux about the style's emergence in mainstream hip hop.

Mumble rap autotune online