[15] Unlike previous full-length releases – from Jay Stay Paid (2009) to Dillatronic (2015) – all edited with unreleased instrumentals, The Diary is a collection of Dilla's vocal performances over his production and that of other producers, such as Madlib, Pete Rock, Nottz, Hi-Tek and Karriem Riggins among others.

It was supported by the singles "The Anthem", "Diamonds", "Give Them What They Want", "The Introduction", "Gangsta Boogie", and "The Sickness", and also includes the 2001 underground classic "Fuck the Police".

[21] This album, which was to be his mainstream debut, was his attempt to take advantage of the attention he gathered after his brightest period as a behind-the-scenes hitmaker and influencer.

[23][24] However, the project stalled and the album was shelved as it was not what MCA had anticipated when it signed Yancey, leading to him being dropped and recording Ruff Draft out of frustration with the major label system.

[21][25] The album was kept in his storage unit in Detroit while he transitioned into living and creating in Los Angeles, before passing with lupus and an incurable blood disease in 2006.

[29] The album's completion was overseen by the estate's Creative Director Eothen "Egon" Alapatt—former general manager of Stones Throw Records and A&R for Champion Sound and Donuts—who previously oversaw the remastering of Ruff Draft in 2007.

"[31] On February 18, 2016, New York City rapper Nas announced on Zane Lowe's Beats 1 radio program that the much-delayed album is expected to be released on April 15, 2016, via his own label Mass Appeal in collaboration with Yancey's imprint.

[38] On March 17, 2016, Nas previewed a previously unheard collaboration with J Dilla during his headlining set at Mass Appeal's Live at the BBQ showcase at SXSW in Austin, Texas.

[46] In anticipation of the album's release, Mass Appeal published online a series of short videos featuring some of the artists who contributed to the project, including Snoop Dogg, Bilal, Hi-Tek, Nottz, and Karriem Riggings among others.

[49] Out of print for over a decade, "Fuck the Police" was remastered and reissued by Pay Jay Productions exclusively for Record Store Day 2015 (April 18).

The song, using original mixes, was released on a badge-shaped 9-inch picture disc single designed by Stones Throw Records' Jeff Jank.

[52][53] On February 11, 2013, "The Anthem", featuring Detroit rap duo Frank n Dank, was made available to stream on Rappcats' SoundCloud.

[54] It was made purchasable at Rappcats.com on 12-inch vinyl on April 15, 2013, packaged with B-side "Trucks" – Dilla's take on Gary Numan's new wave classic, "Cars" – which was previously leaked as an unmixed, unmastered MP3.

[64] Recorded and mixed by Dilla between February and April 2002, the EP includes two tracks that are perhaps two of the best known pieces from the album – the first one was leaked years ago in a low quality unmastered format, and the other was released as a Jaylib-era short-lived promotional single.

[75][76] A day after its release, Eric Torres of Pitchfork gave the song a "Best New Track" designation, writing that "Though it's his idiosyncratic production that earned him his legacy, Dilla was a clear force behind the mic, too.

"[77] Before The Diary was unearthed in full, a previously unreleased track titled "Gangsta Boogie" was premiered on Dr. Dre's Beats 1 radio show The Pharmacy on April 2, 2016.

[79][80] Produced by Hi-Tek, the track features Kokane and Snoop Dogg, whose vocals were recorded after Dilla had passed during the making of the album.

[81][82][83] In a February 2012 interview with Complex, Stones Throw Records founder Peanut Butter Wolf first spoke about the then unfinished piece on which J Dilla gave a shout out to Snoop Dogg.