... though it does have rhythm. (Para. 2)
Meaning: ... though it really has rhythm.
rhythm: n. regular repeated pattern of sounds or movements
That music has a strong rhythm. 這音樂的節奏很強。
Here "does" is used for emphasis (強調) and should be followed by the bare infinitive form of the verb.
He does have a brother in England. 他的確有個弟弟在英國。
n. 強調,重點