This does not apply, however, to the last six membranophones
in the collection, tympani (kettle drums) that have been preserved in the castle not as separate pieces, but in pairs, with one pair still on its original base in the form of a high tripod.
are instruments in which the sound is made by' the vibration of a stretched membrane or skin, such as barrel and waisted drums, kettledrums, band drums.
The author chose to organize the organology section by first addressing general, historical, and regional studies of Spanish instruments, followed with the organological divisions of aerophones, chordophones, idiophones, and membranophones
xxviii-xxxi), which lists the number of instrument types (aerophones, chordophones, membranophones
, and idiophones) and subtypes found in each of the chronological periods.
Seventy-two instruments are distributed evenly among the four players and grouped by timbral or articulatory characteristics into families: lignophones, for example, claves, wood blocks, castanets, and temple blocks; metallophones, featuring Asian cup bells and Chinese cymbals that impart a distinct oriental flavor; membranophones
, such as bongos, timbales, tom-toms, and bass drums; and instruments capable of multiple articulations, such as snare and parade drums.
The timbre of the third sound-scape derives from membranophones
, including two pairs of timpani, tom-tom, and other members of the drum family.
Although no instruments of definite pitch are included, the composer definitely thinks in melodic terms, if "melodic" can be applied to describe the sounds of unpitched membranophones
The instruments are introduced in subgroups of idiophones, membranophones
, and so forth, and each group is summarized in boxed tables for easy review.