The Missing Notebook Rhymes was an unreleased album from 2017 by British-American rapper, MF DOOM. It was in collaboration with Adult Swim, part of their weekly singles program. It was scheduled to include 15 tracks over the course of 15 weeks. However, Adult Swim abruptly cut ties with DOOM, 7 weeks into the project.
The project was initially announced on 7 August 2017 via both Doom and Adult Swim's websites after Adult Swim received a folder from Doom containing 15 rare or unreleased songs. The first track, "Notebook 00 - Negus", was released on Adult Swim's website alongside the announcement. In an interview with Mass Appeal, Adult Swim creative director Jason DeMarco said, "They’re tracks that [DOOM] either doesn’t have a home for, or they are part of other projects which aren’t necessarily complete, but we can sort of tease them . . . It’s sort of a peek at everything he has going on right now." The second track, "Notebook 01 – True Lightyears", was intended to double as the second Missing Notebook Rhyme and also as the first single from Doom's original group KMD's still-unreleased comeback album Crack In Time.
On 26 September 2017, following the release of "Notebook 06 – Pause Tape (Remix)", Adult Swim removed The Missing Notebook Rhymes from their website. In a statement made the next day to Mass Appeal, an Adult Swim spokesperson stated, "Adult Swim is ending our relationship with DOOM, and thus, the remaining Missing Notebook Rhymes will unfortunately have to remain…missing." Despite the news, there was no given reason as to why this decision was made.
On 31 December 2020, in the wake of the announcement of DOOM's passing, Jason DeMarco gave his explanation for why the project had been cancelled in a series of Tweets after three years of silence. He explained that 1. DOOM had not paid his producers/cleared the samples (despite telling them otherwise). 2. His songs were owned by a record label, meaning anything he released, they owned. He didn't give any warning, which led to the label attacking Adult Swim.
Despite the cancellation, people have been theorizing over the missing tracks. A popular theory suggests that DOOM uploaded the remaining tracks to his Soundcloud account. The reasoning behind this was because it contained 8 tracks, the exact number that was missing off the album. That, and the account started posting only 3 weeks after the cancellation. Despite the popularity of the theory, it hasn't been proven by associates of DOOM or Adult Swim. Therefore, the notebooks remain missing.