How many times a week did the slaves have to dance in The Slave Dancer?

In the book The Slave Dancer by Paula Fox, Jessie is forced to play his fife to make the slaves dance every other day. 

After the slaves are brought onto the ship, Jessie is forced to make the slaves dance by playing his fife every other day. Although Jessie does not initially realize his purpose on the ship, he soon ascertains that he was kidnapped to make the slaves dance.  As Jessie’s thoughts reveal:

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In the book The Slave Dancer by Paula Fox, Jessie is forced to play his fife to make the slaves dance every other day. 

After the slaves are brought onto the ship, Jessie is forced to make the slaves dance by playing his fife every other day. Although Jessie does not initially realize his purpose on the ship, he soon ascertains that he was kidnapped to make the slaves dance.  As Jessie’s thoughts reveal:

“It was to perform this service every other morning that I had been kidnapped and carried across the ocean.”

Thus, although Jessie has other tasks as well, playing his instrument for the slaves every other morning is his primary purpose. Jessie has other duties as well. For example, he kills mice, fetches items for the crew, and helps clean the ship. However, his primary role on the ship is playing his instrument to encourage the slaves to dance.

Therefore, the slaves dance every other day. Although Jessie has other responsibilities and personally does not enjoy this activity, he is forced to play his pipe to encourage the slaves to dance.