FöRFATTARE
Hellmer, Kahl

INSTITUTION
Musikhögskolan

SAMMANFATTNING
Five different drummers were asked to perform two short drumming performances to a reference tempo click delivered through headphones – one in 110bpm and one in 160bpm. These performances were analyzed for obvious and, both between the subjects common and individual, timing patterns and – behaviors. Amongst the most important discoveries unveiled were the phenomena which are referred to as drift, flutter and swing. Drift is the drummer’s own timekeeping variations to the reference click, flutter is every strikes individual deviation from the drift itself and swing is a tendency to displace unemphasised hi-hat strikes earlier in time. These behaviors were isolated from each other using various statistical means and described as performance rules, which in turn were translated into C++ code and implemented into a drum machine using the Steinberg VST specification.

Parallel to the analysis of the drum performances a listening test was conducted where the participants were instructed to rank the drum performances in order of their own preference (tightness, credibility and musical feel). The results of the test showed that drummers with a higher amount of swing were more preferred.

The implementation and design is described in general so that readers with little or no programming experiences can understand the main design and functionality of the drum machine. Further details in forms of code examples with explanations are also included which may require some acquaintance with programming in general.

The drum machine has 10 different parameters which can be adjusted by the user; master gain, kick drum flutter, snare drum and tom’s flutter, kick drum’s offset to the hi-hat, snare and tom’s offset to the hi-hat, hi-hat and cymbals’ swing, maximum drift and drift speed. The sound samples that are used include kick drum, snare drum, two different toms, various hi-hat types, ride cymbal, two crash cymbals and a splash cymbal. The drum machine’s design and the sound samples’ style suggests that plug-in be used in the genres of rock, punk rock and various sub-groupings of metal.

Finally an evaluative listening test was conducted to put the performance of the drum machine into context. The results show that the drum machine is significantly more preferred than the drummers’ original performances in 110bpm at 99% confidence level– and at 95% confidence level at 160bpm.

ISSN 1402-1552 / ISRN LTU-DUPP--06/054--SE / NR 2006:054