In comparison to other modern woodwind instruments, the treble oboe is sometimes referred to as having a clear and penetrating voice. The Sprightly Companion, an instruction book published by Henry Playford in 1695, describes the oboe as "Majestical and Stately, and not much Inferior to the Trumpet." Humorously, the sound is described in the play Angels in America as like "that of a duck if the duck were a songbird". The rich timbre is derived from its conical bore (as opposed to the generally cylindrical bore of flutes and clarinets). As a result, oboes are readily audible over other instruments in large ensembles. The highest note is a semitone lower than the nominally highest note of the B♭ clarinet. Since the clarinet has a wider range, the lowest note of the B♭ clarinet is significantly deeper (a major or minor sixth) than the lowest note of the oboe.
Music for the standard oboe is written in concert pitch (i.e., it is not a transposing instrument), and the instrument has a soprano range, usually from B♭3 to G6. Orchestras tune to a concert A played by the first oboe. According to the League of American Orchestras, this is done because the pitch is secure and its penetrating sound makes it ideal for tuning. The pitch of the oboe is affected by the way in which the reed is made. The reed has a significant effect on the sound. Variations in cane and other construction materials, the age of the reed, and differences in scrape and length all affect the pitch. German and French reeds, for instance, differ in many ways, causing the sound to vary accordingly. Weather conditions such as temperature and humidity also affect the pitch. Skilled oboists adjust their embouchure to compensate for these factors. Subtle manipulation of embouchure and air pressure allows the oboist to express timbre and dynamics.