Ahmad Jamal at the Pershing was a defining moment in the career of pianist Ahmad Jamal – it stayed on Billboard's Hot 100 chart for 108 weeks, charting as high as No. 3 and selling over a million copies. Jamal himself cites the album as one of his best, “It's a perfect record” he says matter of factly. And it is. His style was groundbreaking. Miles Davis knew it, “All my inspiration today comes from Ahmad Jamal”, and pianists from Oscar Peterson to Bill Evans, from McCoy Tyner to Ramsey Lewis knew it too. On At the Pershing, his trio had reached a kind of perfection in majestic group interplay. There's so much going on here – his conception of independent roles for bass and drums within a piano trio and his use of rootless chords – okay, Nat King Cole was using them as early as 1938, but Cole was an early influence on Jamal's playing – so as not to clash with a more mobile role for Israel Crosby was highly influential. So too the way he would break open song forms with an ostinato, a precursor of time-no-changes, where he took the music in surprising improvisational directions, and his use of richer left hand voicings than the then prevalent Bud Powell school that fellow piano players were following. His use of dynamics, especially unexpected loud staccato chords in a pianissimo passage, could be as surprising as anything in Haydn's Symphony No. 94, while his inspired use of chord substitutions were as smart as they were unexpected. Jamal was also a master of melodic development and self editing – “Not overplaying is a rule we should abide by”, he said – in fact, the most obvious aspect of his style was a use of space to a degree unusual in jazz up to that point. He had a sense of humour too – he would allude to other songs in his music (not unsubtle full-blown quotes) and he loved to move from 2 to 4, and back again, or juxtapose 2 against 4, or 4 against 2. That Jamal's influence touched some of the greatest musicians in jazz can be heard on Keith Jarrett's version of ‘Autumn Leaves’ on CD3 of At the Blue Note: The Complete Recordings whose form is broken open á la Jamal to elide into a masterful tribute, complete with DeJohnette emulating Fournier's catchy rhythm from ‘Poinciana’ on this set.

As the pianist Hal Galper, who played with Cannonball Adderley among others, noted: “Ahmad's major contributions have yet to be recognised.” That was in 1999. It still holds good.