Aaliyah is described in critical commentaries as an album of R&B, neo soul, and dance-pop, while drawing on an array of other genres such as funk, hip hop, alternative rock, electronica, and Latin music.

The album's producers incorporated synthesizer melodies, fragmented beats, distorted guitar, and eccentrically manipulated vocals and song structures, while much of the lyrics were written by singer-songwriter Static Major, who shared a close friendship and strong rapport with Aaliyah.

Released during a period of peak activity in R&B, critics have since ranked the album as one of the genre's best and most influential records from this era, impacting artists such as Beyoncé, Rihanna, and the Weeknd.

After years of internal and legal conflicts between Blackground, the singer's estate, and the album's creators, Aaliyah was released to music streaming services for the first time in 2021.

Aaliyah recorded her second album One in a Million with producer-songwriters Timbaland and Missy Elliott, releasing it in 1996 to commercial success, and graduated from high school the following year.

"[3] Recording again with Timbaland for the song, Aaliyah experimented with more avant-garde sounds in her R&B and pop music, while singing in a low-register and minimalist style distinct from her vocally-virtuosic female contemporaries.

[5] A third album was planned for February 1999, but Aaliyah postponed its recording to develop an acting career, which led to a starring role in the 2000 film Romeo Must Die.

[10] In 1999, while working on the record in New York City, Aaliyah called and asked Trent Reznor, one of her musical idols, to produce a song, but they could not coordinate their schedules.

[24] MTV News's Gideon Yago reported that she completed its last song on March 9, and the album as a whole was mastered by Bernie Grundman at his studio in Los Angeles.

[32] "Never No More" mixes both older soul and modern hip hop sounds with string arrangements by producer Bud'da, while "Read Between the Lines" is a rhythmic, digital samba with Latin percussion.

[33] Aaliyah's production features synthesizer melodies, vintage syndrums, distorted guitar, staccato arrangements, and layered, eccentrically manipulated vocals.

[34] John Mulvey of NME finds its sound subtle and lacking "bombast and histrionics", while the magazine's Alex Needham likens its "otherworldly", high frequency production to dub reggae and the dark, spacious dance music of Dr. Dre and Massive Attack.

[39] Ernest Hardy of Rolling Stone compares the album's experimentation to the sounds on Outkast's Stankonia (2000), Sade's Lovers Rock (2000), and Missy Elliott's Miss E...

[40] According to Citysearch's Justin Hartung, the record "transforms the confusion of young adulthood into exhilarating freedom", while Billboard's Rashaun Hall says that each song possess a unique emotional identity that accompanies the music's sonic variety.

[43] Among the female empowerment-themed songs, Bob Waliszewski of Plugged In observes a "healthy self-respect" in Aaliyah, who "doesn't put up with unfaithful cads ('U Got Nerve'), mind games ('I Refuse'), self-impressed hunks ('Extra Smooth'), gossip and envy ('Loose Rap'), or physical abuse ('Never No More')".

[44] The key-shifting, drum and bass-influenced "Extra Smooth" addresses an enthusiastic courtship and is inspired by a conversation between Aaliyah and Static about how men try to act suave, while "Loose Rap" is titled after the slang phrase of the same name and dismisses romantic admirers who use trite pick-up lines.

[49] Vibe magazine's Hyun Kim argues that its songs draw focus to her singing more than her previous records, "bringing it to the forefront as opposed to hiding it behind the layered production".

[5] Biographer Christopher John Farley says that she "emotionally detail[s] a song" unlike on her previous albums and that "her gentle voice now seem[s] like something elemental, a kindly wind blowing through the branches of a big tree.

[52] Alex Macpherson from The Guardian writes that "Aaliyah's blank, numbed delivery" on the song "makes being the other woman seem like an emotionally masochistic form of self-medication".

[55] The singer planned to embark on the largest concert tour of her career to support the album, while Blackground and Virgin—heavily invested in the record's success—wanted a single with a high chart placement to help increase sales.

[70] Blackground, which had ended its joint deal with Virgin in November 2001, wanted to send the video for "More Than a Woman" (released on September 4) to domestic outlets, but it required both labels to work together.

[89] Reviewing for The Guardian in July 2001, Michael Odell called Aaliyah a flawless blend of pop and R&B, "as much a brochure for the current state of R&B production facilities" as it is a showcase for its namesake's singing.

[92] Writing for Spin, Clover viewed the record as her most profound work and said she had made "art" out of Timbaland and Static's "formal finesse" by "investing sound schemes with urgency and emotional intricacy".

[93] Connie Johnson from the Los Angeles Times was more critical, finding the production unadventurous and the lyrics lacking the depth and "personal revelation that gives music some immediacy".

[108] In a retrospective review, Steve Huey from AllMusic called it her most consummate record and said it "completed the singer's image overhaul into a sensual yet sensitive adult".

[115] Writing for Vibe's list, Jon Caramanica believed Aaliyah "may be the best soul album of the young millennium" and yet "redefines the category" with music that is "daring in construction, gorgeous from conception ... damn near post-R&B".

[118] As The Independent's Micha Frazer-Carroll writes, acts such as Destiny's Child, Ashanti, Amerie, and Cassie capitalized on the success of the album's "idiosyncratic sound", while Aaliyah's "pared-back vocal phrasing" established an archetype for a "more stoic R&B singer" that would influence vocalists like Ciara and Rihanna.

[4] Timbaland's commercial success with R&B-influenced singers such as Justin Timberlake and Nelly Furtado during the decade was later attributed by The Guardian's Rebecca Nicholson to his experience producing Aaliyah, writing that he "hasn't come close to creating anything as sonically stunning since".

The newspaper's music editor, Ben Beaumont-Thomas, wrote in an accompanying blurb: "This album is lauded for the three masterpieces Aaliyah made with Timbaland—Try Again, More Than a Woman and We Need a Resolution—that lend a serpentine malevolence to her voice, but there are also strong old-school jams and languorous ballads.

Lesser R&B stars match their voice to the beat—Aaliyah's genius, tragically cut short when she was killed in a plane crash, was to slink through it with an almost Latin sense of rhythm.