Stephen Thomas Erlewine of AllMusic states that "much of the record sounds like folk-pop tinged with bossa nova" and describes the songs as "blends of pop, folk, dance, and Latin".

[4] According to Heidi Sherman from Spin "Furtado takes on mainstream urban pop, alternative folk, R&B-soul, and Brazilian samba on Whoa, Nelly!".

[5] Billboard notes that "Nelly Furtado sees no reason for separating rock guitars from pop melodies from R&B/hip hop beats from effervescent bossa nova".

[9] Slant magazine called it "a delightful and refreshing antidote to the army of 'pop princesses' and rap-metal bands that had taken over popular music at the turn of the millennium.

"[15] The sound of the album was strongly influenced by musicians who had traversed cultures and "the challenge of making heartfelt, emotional music that's upbeat and hopeful.

"[17] Stephen Thomas Erlewine of AllMusic gave a positive review while commenting that "Furtado is a restless vocalist, skitting and scatting with abandon, spitting out rapid repetitions, bending notes, and frequently indulging in melismas.

a positive review calling it a "wild-ass pop go-go, filled with songs that pursue adventure yet could still make the hit parades.