Character Analysis
Sergeant Amusa
A member of the "native police," Amusa is the one who comes to Simon to alert him that Elesin is going to commit suicide as part of a Yoruba ritual. Although he has converted to Islam, he still maintains a healthy fear of, and respect for, Yoruba tradition, so he gets super tweaky when he arrives at the Pilkings residence to find Simon and Jane wearing costumes confiscated from local egungun men.
Simon gets really frustrated with Amusa for maintaining such "superstitions" despite his conversion, but Amusa is firm in not wanting (or perhaps, being able) to talk to the Pilkingses while they're outfitted like that.
Praise-Singer
The Praise-Singer's primary function in the play is to dialogue with Elesin and, through their banter, draw out information about Elesin's state of mind and commitment to the task of committing ritual suicide. We don't find out much about him or his inner life, but we do know he's a bit doubtful that Elesin will achieve his goal. And, of course, he's right.
Aide-de-Camp a.k.a. Bob
His primary goal is, as his title implies, to aid the Resident and his fellow British administrators. Like his fellow Englishmen, he isn't super sensitive to the indigenous residents of the area and their traditions, and he gets very aggressive and offensive with Olunde, dropping a racial epithet with ease just because something Olunde says gets Jane emotional. Simmer down, Bob.
Joseph
Joseph is a servant to the Pilkingses. He has converted to Christianity, so he is pretty offended by Simon's fondness for blasphemy.
Bride
She doesn't really get much to do in the play (heck, she doesn't even get a name), but she's the girl Elesin sees wandering around in the market and decides he's going to marry on his last day on earth. She is kind of there in the background for a lot of the action.
H.R.H. The Prince
He doesn't play a major role in the action, but the fact that he's visiting the area makes Simon extra upset about the prospect of Elesin pulling off a ritual suicide, since he doesn't want anything wonky happening to upset the applecart while the royal is around. In this way, he's probably indirectly responsible for the intensity of Simon's botched intervention.
Drummers
The drummers are a pretty constant presence in the play, as their music is key to the rituals taking place. By listening to their music, characters like Olunde and Joseph try to figure out what kind of ritual is being performed and where the characters are at within the ritual.
Women and Young Girls
The women and young girls of the market help assist Elesin in preparing for his big crossover to the afterlife. To that end, when Amusa comes to try to prevent Elesin from achieving his goal, they taunt the policeman and, along with others, drive him away.
Dancers at the Ball
The dancers are just mentioned in passing, as they are simply in the background. But they're there, and since we're here to give you all the details you need, well, now you know they're there.
Constables who help Amusa go to confront Elesin/the women
They don't really do much besides help Amusa confront Elesin and the women. Go team.
The Resident
He is a local British administrator who is hosting the Prince. He chews Simon out for his handling of the Elesin suicide situation, since he's pretty concerned that such shenanigans (if successful) could ruin the royal visit.