The rehearsal space for Hearts of Darkness is more than half the size of a racquetball court. You could drop a tournament-size pool table in there, too, or play a game of horseshoes diagonally across the room.</p><p>But even so, it&rsquo;s barely big enough these days for a Hearts of Darkness rehearsal.</p><p>The band started two years ago as an eight-piece ensemble that wanted to honor Nigerian musician Fela Kuti. Now it has swelled to 17 members and evolved into a funk/rock/soul/hip-hop/jazz orchestra. </p><p>When everyone lines up on stage for rehearsal, band members have to watch which way they turn their instruments and swing their arms. They are surrounded by mics, power cords, amps and monitors.</p><p>Space is tight when your mission is to make a sound that is as large and dense as it is clean and precise. So you keep adding sounds and players to emphasize your point: Make people dance all night.</p><p><strong><span class="subhead">The beginning</span></strong></p><p>Josh Mobley, who plays keyboards and clavinet in the band, initiated the idea and recruited some of the founding members, including Bob Asher and Jolan Smith.</p><p>Asher and other fellow horn players had been in the Dirty Force, a local New Orleans style marching band that formed back in the early 2000s.</p><p>&ldquo;We never said we were a Fela Kuti cover band, but in the beginning we did do several of his songs, like &lsquo;Everything Scattered&rsquo; and &lsquo;Zombie,&rsquo;&ensp;&rdquo; said Alex Smith, who plays alto saxophone. &ldquo;We also rearranged some Fela songs and other Afrobeat songs, which helped us understand how he put songs together.&rdquo;</p><p>In the beginning, Hearts of Darkness didn&rsquo;t have any original numbers. So for its early shows, such as the inaugural performance for Mardi Gras 2008, the band had only about a half dozen numbers in its repertoire.</p><p>&ldquo;All our songs were like 15 to 20 minutes long because we didn&rsquo;t have enough to fill the set,&rdquo; Asher said.</p><p>The band was an eight-piece back then. It has grown to its present configuration, gradually. And it is performing mostly original material. Smith, who studied composition at the UMKC conservatory, is one of the principal songwriters/arrangers. The other is tenor sax player Jolan Smith (no relation). Their styles of writing ultimately produce similar sounds, Asher said, but the Smiths come at it in different ways.</p><p>&ldquo;Alex is very detailed in his arrangements,&rdquo; Asher said. &ldquo;Jolan is looser, less structured, so the band has more room to fill things in.&rdquo;</p><p>At a recent Sunday afternoon rehearsal, 15 of the 17 members were working diligently on two, one-hour setlists for the band&rsquo;s next show: Halloween night at Davey&rsquo;s Uptown Ramblers Club. Rehearsals typically last four hours. During show weeks, the band may rehearse twice.</p><p>&ldquo;A lot of us spend most of our spare time on this band,&rdquo; Asher said.</p><p>&ldquo;We&rsquo;re not just a rock band that can learn a song in two or three practices,&rdquo; Smith said. &ldquo;Sometimes a song can take two to three months to get.&rdquo;</p><p>They attempted one of those more difficult numbers during the Sunday rehearsal. Twice, the performance fell apart in the middle when the horn and rhythm sections couldn&rsquo;t navigate one of the many irregular turns and changes in the composition.</p><p>&ldquo;We&rsquo;re not gonna do that one,&rdquo; Asher said. &ldquo;We don&rsquo;t want to (mess) up the middle of the first set.&rdquo;</p><p>No one objected, so they moved on to another song, &ldquo;Terror Flu.&rdquo; This one, too, is a blizzard of shifting and syncopated rhythms and brassy horn lines dancing atop a deep, funky bass riff and a bed of beats from drummer Sean P. Branagan and congo player Mikael Spears.