ophicleide

As nouns the difference between ophicleide and bass

is that ophicleide is a keyed brass baritone bugle, now replaced by the tuba in orchestral music while bass is a low spectrum of sound tones.

As an adjective bass is

of sound, a voice or an instrument, low in pitch or frequency.

As a verb bass is

to sound in a deep tone.

As a proper noun Bass is

an English brand of bottled pale ale.

As nouns the difference between euphonium and ophicleide

is that euphonium is (musical instruments) a valved brass instrument, a sax horn, the tenor of the tuba family of instruments, having the appearance very similar to that of a tuba it is similar to and often used instead of a "baritone" horn (a true baritone has a cylindrical tubing, while the euphonium tubing is conical, though they both cover the same range of tones this relationship is also between the trumpet [cylindrical] and cornet [conical] respectively) while ophicleide is (music) a keyed brass baritone bugle, now replaced by the tuba in orchestral music.