VITA 2010

  Vienna Talk 2010 on Music Acoustics
"Bridging the Gaps"
      September 19–21


Percussion instruments (T. Rossing): Description

In this session we welcome all papers that present new findings about percussion instruments.

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Rossing; Thomas: 
(Keynote) / O
The small to medium amplitude vibrations of plates, gongs, and steelpans can be described in terms of normal modes of vibration. By using various techniques for modal analysis, the modal frequencies, modal shapes, and damping can be determined. Optical techniques generally give the highest spatial resolution. At large amplitude, interesting nonlinear effects are often observed. We review some vibrational properties of plates, gongs,Caribbean steelpans, and the HANG, a hand-played steel instrument. Both linear and nonlinear behavior will be described.
Worland; Randy: 
(Invited) / O
Orchestral crotales are small bronze cymbals shaped like disks with an added central mass. Each crotale produces a definite pitch when struck with a mallet, with a typical set encompassing two chromatic octaves, from C6 to C8. Contemporary composers writing for percussion often incorporate unconventional playing techniques with the use of traditional instruments. Among these extended techniques is the lowering of gongs and crotales into water as they are being struck, resulting in a glissando effect that involves changes in both pitch and timbre. The orchestral crotale has a relatively simple geometry and overtone structure, making it an appropriate starting point for the study of this performance technique. Results of an experimental investigation of crotale vibrational modes in water are presented, along with a simple effective mass model describing the various observed effects. Mode frequencies, shapes, and degeneracies are investigated as a function of water depth using electronic speckle-pattern interferometry.
In this work some considerations are made about drum sets features, making comparisons between two different drum sets, played by two different drummers, performing the same simple 4/4 rock grooves with different rhythm and speed (120 bpm and 60 bpm). Some comparisons are also made between the whole sound pressure level of the drum sets, and each single piece of the drum set separately played.

Drum sets characterizations are made analyzing many multichannel measurements, carried out in the Acoustics Laboratory of the Department of Applied Physics of the University of Padova (Italy). Measuraments are made both in the reverberant room, for sound power level characterization of the drum sets according to iso 3741, and in the double rooms of the laboratory according to ISO 140-3, to determine the behaviour of building structure with respect to drum set sound.
Handbell modes are generally identified by two indices (m,n). The first one counts the number of nodal lines crossing the crown, while the second one counts the number of circumferential nodal lines. It is notable, that for values of m>3 (depending on bell size) the n=0 modes are missing, instead, an additional set of n=1 modes appears, for which the circumferential nodal line is located very near the mouth of the bell rather than as normally, approximately midway between the crown and the mouth of the bell. These modes which have frequencies above the (m,1) modes are labeled as (m,1*) modes. In an effort to understand the influence of geometry on mode shapes, Finite Element studies with increasingly complex geometry were undertaken. It was discovered that the imposition of overlapping positive and negative curvatures is essential for the formation of the (m,1*) modes.
Banner Pictures: (c) PID/Schaub-Walzer