[2] As a secondary composer to John Lennon and Paul McCartney in the Beatles,[3] Harrison began to establish his own musical identity through his absorption in Indian culture,[4][5] as well as the perspective he gained through his experiences with the hallucinogenic drug LSD.

[1][12] Authors Russell Reising and Jim LeBlanc cite the song, along with "Rain" and "Within You Without You", as an early example of the Beatles abandoning "coy" statements in their lyrics and instead "adopt[ing] an urgent tone, intent on channeling some essential knowledge, the psychological and/or philosophical epiphanies of LSD experience" to their listeners.

"[14] Author Robert Rodriguez views the song as reflecting the effects of Harrison's search for increased awareness, in that "the faster and more wide-reaching his thoughts came, the greater the struggle to find the words to express them".

[27] According to Rodriguez, "I Want to Tell You" is an early example of Harrison "matching the music to the message",[20] as aspects of the song's rhythm, harmony and structure combine to convey the difficulties in achieving meaningful communication.

[27][nb 2] With the return to the I chord for the guitar riff, the harmonic progression through the verse suggests what author Ian MacDonald terms "an Oriental variant of the A major scale" that is "more Arabic than Indian".

[35] Musicologist Walter Everett comments on the aptness of the conciliatory lyric "Maybe you'd understand", which closes the second of these sections, as the melody concludes on a perfect authentic cadence, representing in musical terms "a natural emblem for any coming together".

[23] On the Beatles' recording, the group vocals over this section include Indian-style gamaks (performed by McCartney)[25] on the word "time", creating a melisma effect that is also present on Harrison's Revolver track "Love You To"[36] and on Lennon's "Rain".

[39] Author Ian Inglis notes that lines such as "My head is filled with things to say" and "The games begin to drag me down" present in modern-day terms the same concepts regarding interpersonal barriers with which philosophers have struggled since the pre-Socratic period.

[18] MacDonald cites the lyrics to the first bridge – "But if I seem to act unkind / It's only me, it's not my mind / That is confusing things" – as an example of Harrison applying an Eastern philosophical approach to difficulties in communication, by presenting them as "contradictions between different levels of being".

"[1][12][nb 4] Further to Laing's reading of the song's message, author and critic Tim Riley deems the barriers in communication to be the boundaries imposed by the anxious, Western concept of time, as Harrison instead "seeks healthy exchange and the enlightened possibilities" offered outside such limitations.

[52] After reduction to a single track on the four-track master tape,[55] their performance consisted of Harrison on lead guitar, treated with a Leslie effect, McCartney on piano and Ringo Starr on drums, with Lennon adding tambourine.

[58] Like "Eight Days a Week", the completed track begins with a fade-in,[23][25] a device that in combination with the fadeout, according to Rodriguez, "provided a circular effect, perfectly matching the song's lack of resolution".

[61] The process of recording the bass separately from a rhythm track provided greater flexibility when mixing a song,[61] and allowed McCartney to control the harmonic structure of the music by defining chords.

[72] For the North American version of Revolver, however, Capitol Records omitted "Doctor Robert", together with two other Lennon-written tracks;[73] as a result, the eleven-song US release reinforced the level of contribution from McCartney[74] and from Harrison.

[75][nb 8] According to Beatles biographer Nicholas Schaffner, Harrison's Revolver compositions – "Taxman", which opened the album, the Indian music-styled "Love You To", and "I Want to Tell You" – established him as a songwriter within the band.

[77][nb 9] Recalling the release in the 2004 edition of The Rolling Stone Album Guide, Rob Sheffield said that Revolver displayed a diversity of emotions and styles ranging from the Beatles' "prettiest music" to "their scariest", among which "I Want to Tell You" represented the band at "their friendliest".

"[20] Melody Maker's album reviewer wrote that "The Beatles' individual personalities are now showing through loud and clear" and he admired the song's combination of guitar and piano motifs and vocal harmonies.

[80] In their joint review in Record Mirror, Richard Green found the track "Well-written, produced and sung" and praised the harmony singing, while Peter Jones commented on the effectiveness of the introduction and concluded: "The deliberately off-key sounds in the backing are again very distinctive.

"[81] Maureen Cleave of The Evening Standard expressed surprise that Harrison had written two of the album's best tracks, in "Taxman" and "I Want to Tell You", and described the latter as a "fine love song".

[83] While commenting on this phenomenon in September 1966, KRLA Beat's reviewer described "I Want to Tell You" as "unusual, newly-melodic, and interesting" and lamented that, as with songs such as "She Said She Said" and "Yellow Submarine", it was being denied the recognition it deserved.

Gilmore considered this innovation to be "perhaps more originally creative" than the avant-garde styling that Lennon and McCartney took from Karlheinz Stockhausen, Luciano Berio, Edgar Varese and Igor Stravinsky and incorporated into the Beatles' work over the same period.

'"[27][nb 10] In his overview of "I Want to Tell You", Alan Pollack highlights Harrison's descending guitar riff as "one of those all-time great ostinato patterns that sets the tone of the whole song right from the start".

[91] In his review of the song for AllMusic, Richie Unterberger admires its "interesting, idiosyncratic qualities" and the group vocals on the recording, adding that McCartney's singing merits him recognition as "one of the great upper-register male harmony singers in rock".

[109] In November 2002, a year after Harrison's death, Jeff Lynne performed "I Want to Tell You" at the Concert for George tribute,[110] where it served as the first song of the main, Western-music portion of the event.

[119] While Pitchfork Media's reviewer dismisses the Melvins' performance as a throwaway version of a "Beatles classic",[120] Jared Skinner of PopMatters describes it as "solid proof of their ability to make loud, gleeful rock 'n' roll".