24- and 48- Div Trills Guidance notes
Trills on a standard, 3-valve instrument
General rules for writing trills:
• Semitone and tone trills are possible throughout the range. Some trills larger than a
tone may be possible: composers should check with individual players
• When one finger is moving (depressing and releasing a valve) the trill will be
smoother and faster than if two fingers are moving: the latter tends to sound like
sixteenth notes (depending on speed) rather than a genuine trill
• Semitone trills which move from an open position are particularly effective; tone trills
which move from an open position are possible but more cumbersome
• Trills below middle C are awkward
• Trills which have no common valve are particularly difficult to control (e.g.: 1-2; 2-3;
1-3). Common valves give stability and security to the right hand.
Notes for composers: remember that if a valve slide is in use for one of the
fingerings it won't necessarily effect the other fingering – check the relevant
fingering chart to make sure.
Quarter-tone Trills
• Quarter-tone trills tend not to be possible where pitches share the same name-root
(e.g. D and D quarter-sharp, although there are occasional exceptions) or where they
share the same fingering (where one of the pitches involves a valve slide adjustment:
trills on valve slides are ineffective)
• Trills can often be aided by preparation or early positioning of the valve slides
• In the case of an added fourth valve, this does not particularly benefit trilling. Trills
using the rotary valve described on this site are possible but somewhat 'measured'. A
fourth piston valve would allow effective trilling on the quarter-tone valve.
Interval Look up Charts - Introduction
The interval look-up charts are intended as a further tool to assist in the development of a
thorough understanding of the microtonal environments presented on this website: 24-, 48-
and 19-div.
Using the charts, it is possible to look up intervals in 24 Microtonal Studies, which are shown
in their abbreviated form. The interval may then be pencil-marked in, a procedure which
should be followed until interval-spotting becomes automatic.
The charts are particularly useful for those intervals which are difficult to identify at first
sight. For example, B quarter-flat to D may register relatively quickly as a quarter-sharp
minor third on the basis that B to D is a minor third and the quarter-flat widens that interval.
On the other hand, C three-quarter sharp to E quarter-sharp may be harder to spot (as a
minor third). For such intervals the charts provide verification and reassurance.
Intervals in 19-div are much easier to learn and recognize because many look, and are
described, in exactly the same way as 12-div intervals. The chart may still be useful in the
early stages, however, and is included for this reason.
USING THE CHARTS
The Interval Look-up Charts are presented in a form which allows for duplication and
enlargement. They are presented in the order in which the divisions are presented (i.e. 24-;
48-; 19-div). As the A3-size files are too large for most domestic printers it is suggested
that they are downloaded and by your local high-street printer for printing in these larger
formats.