By Sarah Rodman

Counting the number of Benjamins one has amassed is common in hip-hop. Accounting itself, however, is not usually fertile ground for nascent rappers.

But it was while studying the finer points of bookkeeping in high school that the members of Senegalese rap trio Daara J hatched their plan to spread the word about hip-hop's African roots.

''Our parents are all accountants and teachers," says Daara J leader Faada Freddy via e-mail, en route to a tour stop in Mexico. ''We were supposed to do the same except we all loved music as well. We had to convince our parents that we could make money from singing."

Freddy and his partners in rhyme, N'Dango D and Aladji Man, all in their 30s, haven't broken the bank just yet. But they have managed to propel their activist jams far beyond the borders of their hometown of Dakar.

On the strength of their third album, 2003's critically acclaimed ''Boomerang," the rappers were chosen by Peter Gabriel to appear at the Live 8 show last year in Cornwall, England; scored the BBC world music award for best African act in 2004; and have circled the globe with equally politically minded Western rap artists Public Enemy, Wyclef Jean, and Mos Def. An upcoming US tour brings the trio to Boston for the 31st Bastille Day Street Dance alongside fellow African, Francophone fusionists Amadou & Mariam and Daby Toure on July 14.

Daara J hasn't forgotten its studies in a blur of Cristal-fueled success, however. Whether it's taking corrupt politicians to task or urging young people to vote for change, ''Boomerang" is all about accountability.

''This is very much part of our culture to transfer messages via our songs," Freddy says.

Despite the urgent nature of the material, ''Boomerang" is brimming with optimism. Daara J -- which means ''school of life" -- weds buoyant Afro-Cuban rhythms, crisp hip-hop grooves, and soulful R&B vocals to lyrics that tumble out in a celebratory cultural stew of French, English, Spanish, and their native Wolof.

The album's title refers to the group's belief that hip-hop was, if not born, at least seeded in Africa. ''When we were taken from Africa to be slaves and sent to all parts of the world, a form of rap called tasso, which is rhythm-based storytelling, already existed," explains Freddy. ''When it left the motherland, it remained dormant for a while. And then one day it was awakened. African-Americans forgot where it originally came from. It was a natural evolutionary process for it to come back to Africa, where we have developed it further!"

It is precisely that development that caught the ear of Wrasse Records honcho Ian Ashbridge and what he thinks has set Daara J apart from some very serious competition: There are reportedly 6,000 hip-hop acts in Dakar alone.

''I think Daara J are smart. They're not trying to be American," says Ashbridge, whose UK-based label is also home to artists such as Seu Jorge and Ladysmith Black Mambazo. ''I think that here there are guys that are being influenced by MTV, but at the same point they are mixing their roots with what they're getting from the Western world and turning it into something new."

They have also turned it into sales that, though modest by multiplatinum US standards, are helping the members, who are married with children, turn a profit. So that accounting course should be coming in handy, right? Says Freddy, likely with a laugh, ''not really."

Daara J performs at the French Library and Cultural Center's Bastille Day festival on Marlborough Street on July 14. Street dance and fair is from 6-11 p.m. Tickets go on sale June 1. Call 617-912-0400 or visit www.frenchlib.org.