1.
If you jazz something up, you make it look more interesting, colourful, or exciting. (INFORMAL)
Mary Ann had made an effort at jazzing up the chilly modern interiors...
I don’t think they’re just jazzing it up for the media.
PHRASAL VERB: V P n (not pron), V n P
2.
If someone jazzes up a piece of music, they change it in order to make it sound more like popular music or jazz.
Instead of playing it in the traditional style, she jazzed it up...
Stephen and I are going to ~ the love songs...
PHRASAL VERB: V n P, V P n (not pron)