Sound production in four mallet marimba performance: The role of limb velocity variability


Sound production in a percussion context like marimba results from using two mallets held in each hand to strike a unique bar/target location. If the mallets contact the bar above the resonator below, optimal sound production occurs. This study examined mallet accuracy to further understand mechanisms underlying motor control in marimba performance. Thirteen percussionists played a four-mallet excerpt in three tempo conditions including slow, intermediate, and fast. Mallets were held proximal to the pinky (mallet 1: left hand, mallet 4: right hand) and thumb (mallet 2: left hand, mallet 3: right hand). Motion tracking measured movements and velocities of the mallets, wrists, and elbows. Instructions were to terminate each mallet's movement onto a visual target located on the marimba's bars above the resonators. Contrasting each mallet's terminal position with its unique target location when all four mallets contacted the marimba simultaneously (i.e., playing chords) assessed mallet accuracy. Velocity analyses examined the variability of upper-limb and mallet movements. It was hypothesized that increases in limb velocity variability would negatively impact mallet accuracy. The results showed that accuracy was lowest in the fast vs. the intermediate and slow conditions within the outer mallets (i.e., 1, 4). In both elbows and wrists, velocity variability was greater in the fast vs. the slow condition. It may be surmised that increasing velocity variability of limb movements reduces mallet accuracy resulting in suboptimal sound production in the outer mallets specifically. Motor skill acquisition in marimba performance may be facilitated by emphasizing temporal control in the upper-limbs.

Acknowledgments: The Canada Foundation For Innovation and the Percussion Department in the Faculty of Music at U of T