Final answer:
The sentence 'Jamel organized the festival, and he called all the bands' is a compound sentence, consisting of two main clauses joined by a coordinating conjunction.
Step-by-step explanation:
The structure of the given sentence 'Jamel organized the festival, and he called all the bands' is a compound sentence. A compound sentence is made up of two or more main clauses that are equally important.
In this sentence, the two main clauses are 'Jamel organized the festival' and 'he called all the bands'. These two clauses are joined by the coordinating conjunction 'and'.
Therefore, the sentence is a compound sentence because it contains two main clauses joined by a coordinating conjunction.