A pedal has a base, two supporting posts, a pedal plate, a first shaft, a second shaft, a chain assembly and two beaters. The pedal plate is mounted pivotally on the base. The first and second shafts are rotatably mounted respectively on the supporting posts, are connected concentrically together and are capable of rotating independently. The chain assembly connects the pedal plate to the first shaft. The beaters are mounted respectively on the first and second shafts. The concentrically connected first and second shafts serve as a crossbeam between the supporting posts to reinforce the structurally strength of the pedal and obviate additional crossbeams that limit the pivoting range of the pedal.