'THE WORLD REVOLVING', despite appearing in only four songs, is easily one of the most important leitmotifs in Deltarune, pertaining to the 'secret bosses' fought in each chapter (thus far Jevil and Spamton NEO).
It's split into two somewhat distinct parts:
('THE WORLD REVOLVING' sections A and B, as heard in THE WORLD REVOLVING)
It's worth noting that both secret bosses thus far utilize the motif in the same way:
Once in their ALL-CAPS battle theme:
(THE WORLD REVOLVING for Jevil and BIG SHOT for Spamton NEO)
And once in an extraneous theme:
(The Circus for Jevil and Dialtone for Spamton NEO)
Worth noting is that both The Circus and Dialtone use a 3/4 waltz riff pattern.
(See also: 'On the Origins of Undertale and Deltarune's Leitmotifs')
Finally, I highly recommend Andrew Cunningham's (ahem)
Everything About Gaster's Motif in the DELTARUNE Soundtrack - A Musical Mythbusting Odyssey,
which covers the motif in discussing its relation to 'Gaster's Theme'.
Although I agree with the conclusion the video comes to, I still think that 'THE WORLD REVOLVING' (A.K.A. the "Freedom Theme") is enough of its own thing to warrant considering it a leitmotif separate from 'Gaster's Theme'.