“In Brazil, we sometimes say you have to have a big hat to play music,” says clarinetist and saxophonist Nailor “Proveta” Azevedo, a veteran musician best known among international jazz fans as a founding member of Banda Mantiqueira. “We have a lot of kinds of ideas, a lot of different rhythms.”

Preferring to go by his nickname “Proveta,” which refers to the fact that he was one of the first test tube babies in Brazil, he finds ways to express himself in various settings — from large-sized ensembles like Banda Mantiqueira to smaller combos like his current quintet.

“I can’t speak for everyone, but I arrived at some things on my own by hearing and feeling what I have in my heart,” says Proveta. “It’s for real. I like the performances where every musician is playing for his life and playing what they feel and think in the moment.”

Apparently, the musicians in Proveta’s current combo have the right feel and sense of purpose. The chemistry seems ideal.

His band features Alessandro Penezzi on the seven-string guitar, Danilo de Brito on mandolin, Roberta Valente on pandeiro (a hand-held percussion instrument), and André Mehamari on piano. The quintet performs at the Cistern as part of the Wachovia Jazz Series this week.

“Each of these musicians play with creativity, dialogue, and a lot of sensitivity,” says Proveta. “The compositions of the older composers are very consistent. It is very enjoyable and very challenging as well. We will also touch on very interesting compositions of the musicians in this group.”

Some of the classic Brazilian pieces in their set list include “Aguenta seu Fulgencio,” “Vôo da Mosca,” and “Bola Preta,” as well as selections by legendary Brazilian composers Pixinguinha and Dori Caymmi.

“We’ll take basic choro or maybe we’ll play a baião — but it’s like a choro-baião,” says Proveta. “It’s a little different. Because the musical styles are very regional, some bands play their styles only. In São Paulo, our band tries to do all sorts of different things. We are musicians, and we want to be creative, so we try to play a lot of things from Brazil — mainly things we can feel as musicians.”

Popular in its earliest forms during the 1920s and ’30s, choro (pronounced “shoh-roh”) was a harmonically complex musical form based on improvisation, African and European tonal phrases, and syncopated rhythmic patterns (similar to samba and bossa nova).

“I used saxophone and clarinet to play choro, the old style of music in Brazil, with my father,” he says. “Choro is used for all instruments. It’s like jazz in the United States. I arrived in professional music knowing choro and samba and all of the styles.”

Percussion and stringed instruments were the core components of choro, with woodwind, brass, or keyboard instruments taking most of the solos and lead melodies. One of the most celebrated and prolific composers of choro was the flautist Pixinguinha.

While Pixinguinha’s classic pieces influenced Proveta as he learned to play, the young man was equally inspired by the jazzy sax work of Richie Kamuca, a be-bop player in the American West Coast jazz scene in the 1950s and ’60s. Kamuca’s impassioned work with such acts as Stan Kenton, Woody Herman, Chet Baker, and Shelly Manne caught Proveta’s ear.

“Kamuca was a famous player from four brothers,” says Proveta. “I listened to him and a lot of other jazz musicians like Charlie Parker and Phil Woods. I had a great passion for their styles of music, and I tried to bring that into the music of Brazil. Free and fluid — it was like a new life for the choro music. I developed a passion for improvisation through jazz.”

Despite their small size, they make a big sound.

“We have our own combination of four instruments, but try to have the same impression as a big band,” Proveta says. “It’s very spirited and very strong. There’s a lot of power … a lot of color, swing, rhythm, and melody.”