Genesis and creation are popular subjects among jazz artists composing extended works. Duke Ellington’s “In the Beginning, God,” Randy Sandke’s “Genesis 1,” and Stefon Harris’s “Grand Unification Theory” have all successfully explored this idea. But none has succeeded like the composer and saxophonist Wayne Shorter, whose classic 1965 concept album “The All Seeing Eye” rendered the beginning of time as a first-person narrative.

On Wednesday night at the Iridium, the first two movements of “The All Seeing Eye” – it was written as a fivepart suite – were performed by a newly formed Shorter tribute band named Endangered Species. Assembled by the trumpeter and arranger David Weiss, this may be the first such ensemble to devote itself to the music of an active jazz icon. But though Mr. Shorter is still very much alive, he is unlikely to perform works like “The All Seeing Eye” again.

This remains Mr. Shorter’s most adventurous work. It took him closer than he would ever come to avant-garde jazz and served as a genesis of many things in his career – in later years he composed an increasing number of extended suites and explored the spiritual modes of both Western and Eastern religions, even though his music veered toward electronic vistas.

The 1965 work was originally written for eight musicians, the largest acoustic combination Mr. Shorter has ever gathered in a studio. Endangered Species adds four musicians to the ensemble, and Mr. Weiss has fleshed out Mr. Shorter’s score, turning it into a more orchestral work by taking background figures originally played by individual horns and writing them out for entire sections.

The first two movements, “The All Seeing Eye” and “Genesis,” occupy the entire first side of the original LP; Mr. Weiss’s band played them without a pause on Wednesday night. The music opened slowly with a dissonant, out-of-tempo passage by the horns, then drums and piano joined in to introduce the first soloist.Trumpeter Jeremy Pelt played an intense, probing solo in the same spirit as the one with which Freddie Hubbard christened the work in 1965.

This is music of extreme contrasts. Throughout the piece, the horn solos, mostly backed by just bass and drums, build from whispers to screams as if to depict the formation of Pangaea-like continents. At times the soloists seem completely free, but the carefully orchestrated backgrounds remind us that even what is improvised in this music – as it is in God’s universe – was carefully considered beforehand.The piano solos, played by Xavier Davis at Iridium (and by Herbie Hancock on the album), have much more of a classically Gothic texture, and are much quieter and contemplative in nature – almost if Mr. Shorter were using the keyboard to convey the voice of God.

Mr. Weiss included other Shorter works in Endangered Species’s 75-minute set, including “Fall,” a modally based piece written for Miles Davis, and “Mr. Jin,” an Oriental bebop written for Art Blakey’s Jazz Messengers. Both pieces were originally written for quintets, but were strikingly expanded for the big band.

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Another composer is being celebrated in Midtown, one who also specialized in infectious melodies, ambitious structures, daring harmonies, tricky meters, and conceptual long-form works – and whose name rhymes with Mr. Shorter’s. Some two dozen Cole Porter songs, both well-known standards and buried gems, are served up like hors d’oeuvres at the Oak Room in “A Swell Party: RSVP Cole Porter,” performed by KT Sullivan and Mark Nadler.

Up to now, Ms. Sullivan and Mr. Nadler have worked extensively as a singing duo, but with this show they have added a third “voice,” saxophonist Loren Schoenberg. His tenor not only supplies obbligatos and various accompaniments but participates so much in Mr. Nadler’s ambitious arrangements that the act becomes a trio. They make this plan plain in the second number, “Let’s Do It,” in which Mr. Schoenberg’s tenor is given the responsibility of “singing” the title line each time it occurs.

Ms. Sullivan is especially moving on Porter’s minor-key masterpiece “So in Love,” making even Porter’s “joy delirious” sound suitably melancholy and sexy simultaneously. Mr. Nadler pulls out all the stops in the seldomheard “You’ve Got That Thing,” which starts small and builds slowly, like a herd of elephants approaching from far away.

Mr. Nadler has also constructed several ambitious set pieces out of subsets of Porter songs. The finale, for example, is an assemblage of songs about dreaming and dancing. It starts with Mr. Schoenberg playing “Begin the Beguine” unaccompanied, while the two principals slip offstage and into something more comfortable.They return in sleepware, she in a modest negligee, he in a smoking jacket, which is how they finish the show. If Cole Porter had written “The Pajama Game,” this is what it would have been like.

Endangered Species will perform again March 22 & 29 at Iridium (1650 Broadway at 51st Street, 212-582-2121). Sullivan & Nadler until April 1 at the Algonquin Hotel’s Oak Room (59 W. 44th Street, between Fifth and Sixth Avenues, 212-419-9331).