that it's a "complicated process that has no right answer".
There can be concerns over whether putting out someone's music after they've died is the right thing to do, with fans worrying about the impact it might have on artist's legacy.
"I think sometimes the families try and capitalise on the music in a way that's not what the artist would've wanted", says 26-year-old Henry Dean.
He's a photographer and Mac Miller fan, and he worked with the rapper a few years ago on a magazine shoot. He spoke to Radio 1 Newsbeat at a free event to celebrate the UK release of the new album.
Henry is pictured here with some of his art of Mac
"Posthumous music is a murky area. I'm always sceptical of whether it's being handled right. Obviously, I don't know Mac's inner circle so I can't judge.
"Artists have banks of thousands of songs and not all of them are meant to come out, so I'm hoping everything on this album is stuff that he was actively planning on releasing."
In their post on Instagram, Mac's family said: "We simply know that it was important to Malcom for the world to hear it"
"The look on his face when everyone was listening said it all."
After the launch event in east London, fans seemed pleased with the result.
Paris, Lauren, Ray and Simone were excited to hear Mac Miller's new album
"It sounded perfect, it was very Mac Miller," says 23-year-old fan Paris.
"You could tell it was something he would've wanted to come out had he been here."
Paris' friend Lauren agrees.
"I was a bit worried it was going to be Mac's voice on someone else's songs, because it wasn't finished by him. Having listened, it was a very Mac album all the way through.
Mac Miller was 26 when he died from an accidental overdose
Roisin O'Connor is the music correspondent for the Independent. She was invited to listen to the album by the music producers who worked on it.
"Hearing them talk, it was made very clear that the family had given their blessing for the album to be released," she says.
"It wasn't just scraps of material, it was intended to be an album. He'd completed a lot of it before his death - it was final touches. To release it was almost like fulfilling his wishes."
She says that while posthumous music releases can be treacherous territory, Circles feels like a complete body of work from Mac himself.
"It's him at his creative peak. He sounds at peace, and philosophical about getting through each day."
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