Assertion: brass's valve | /r/CapableOf | lower the pitch
Facets:
value: by a perfect fourth
type: OTHER
Source sentences:
text: Since valves lower the pitch, a valve that makes a pitch too low (flat) creates an interval wider than desired, while a valve that plays sharp creates an interval narrower than desired.
text: In instruments with a fourth valve, such as tubas, euphoniums, piccolo trumpets, etc. that valve lowers the pitch by a perfect fourth; this is used to compensate for the sharpness of the valve combinations 1–3 and 1–2–3 (4 replaces 1–3, 2–4 replaces 1–2–3).