Where can I find information on the slide trombone?

In practice many players play first position with the slide extended a slight amount; this allows vibrato to be used and prevents injury to the player from striking the slide against its stop. Extending the slide from one position to the next lowers the pitch by one semitone. Thus, for each note in the harmonic series a downwards interval of up to a tritone may be added to the first position note, making the lowest note of the standard instrument an E natural. However, most professional trombonists can play lower "falset" notes and much lower pedal notes (first partials or fundamentals, which have a peculiar metallic rumbling sound) on the instrument. Table 1 below illustrates the seven positions of the trombone slide and the harmonic series associated with each. It may be noted that these positions are subject to adjustment, compensating for imperfections in the tuning of different harmonics. The fifth partial is rather flat on most trombones and usually requires a minute shortening of the slide position to compensate; other small adjustments are also normally required throughout the range. Note that trombonists also make frequent use of alternative positions (shown to the right of the dividing line in the diagram below); for instance, Bb4 may be played in first or fifth positions. This allows a player to produce a glissando to or from a higher note on the same partial, if such effect is desired.