Assertion: double bass's string | /r/HasProperty | put in groups of two
Facets:
value: at the unison
type: MANNER
value: at octave
type: TEMPORAL
value: together
type: MANNER
Source sentences:
text: A variety of tuning options and number of string courses (courses are when strings are put together in groups of two, often at the unison or octave) have been used to extend the range of the instrument, or facilitate different modes of playing, or allow for different playing sounds.