Forming a six-member band without a guitarist is preposterous, but Fitz and the Tantrums make it work. Six is just the right number for the band's larger-than-life Motown-influenced jams — adding anything else would be overkill. Two vocalists, a saxophone, and a keyboard are just the right mix of tones to create the band's distinct sound, which plays out like a grandparent's fond memories of hearing The Supremes for the first time. The Tantrums pay homage to the classics without being a copycat band, even though they certainly look the part. Led by Michael "Fitz" Fitzpatrick, the group usually performs in matching suits, with Noelle Scaggs sporting a chic retro dress. Scaggs has a good voice, but the band defies a typical soul trope by having her sing backup vocals and play tambourine. Fitzpatrick leads with a pop urgency that matches the energy of the rest of the band, making for memorable live performances. This is the second time Fitz and the Tantrums have performed in Phoenix and the show has already sold out, making it a testament to the band's overnight success.