Setting the pitch
As you saw above, you set the pitch of any
note by giving its musical name - eg, C E
G. Sharp notes are prefixed by # (eg #C)
and flat notes by $. Your 'instrument'
covers two octaves in the key of C, and
uses letters c to b for the notes in the lower
octave, C to B in capitals for the higher
one.
Any number of notes within these two
octaves can be played one after another,
eg
10 LET a$="cfedafgCFEDAFGCC"
20 PLAY a$
If you want to span more than just two
octaves, you can change the overall pitch
of your 'instrument' by using the octave
command 0 followed by a number from 0
to 8. if you do not specify an octave (as in
the example above) it is automatically set
to 5 (the range containing middle C). The
octave command remains in force for all
notes which follow it until a new octave
command is given.
This program lets you hear the same
tune played in a higher octave (just add the
O7 to your earlier program)
10 LET a$="O7cfedafgCFEDAFGCC"
20 PLAY a$
Try changing the octave number
progressively to hear the full pitch range
which your Spectrum 128 can produce.
Notice that some of the very lowest notes
in octaves 0 and 1 will not be reproduced
at the right pitch except through the MIDI
output. The Spectrum 128 will simply play
them at the lowest pitch possible.
Since each pitch range covers two
octaves, two adjacent ranges overlap. For
example, the high part of 04 contains the
low part of 05 (see the diagram below).
Note that you can extend any range
slightly by using a series of sharps (####)
or flats ($$$$) to raise the pitch of
individual high notes or lower the pitch of
low ones.
Note duration
If you do not specify the length of each
note, they will all be played at the same
length (as crotchets) as in the examples
above. You can fix the length of any note
or series of notes by prefixing it with a
number from 1 to 12. This program lets
you hear the different note duration with
numbers from 1 to 9.
10 LET a$="1C2C3C4C5C6C7C8C9C"
20 PLAY a$
Pitch values for making music with PLAY |
This diagram shows how you
can create different notes
using the Spectrum 128's
octave command.
The command O followed
by a number from 0 to 7 sets
the Spectrum 128 to a range
of two octaves beginning |
with a C. The diagram shows
the complete range of notes
covered by O4. O5, and O6.
Adjacent octave ranges
overlap, so the same notes
appear in the upper part of
one range and the lower part
of another. |
Individual notes within an
octave range are set by using
the letters c to b in lower case
for the lower notes and C to B
in capitals to give the notes in
the upper octave.
Placing a # before any
note letter gives a sharp note
- a $ flattens it. |
|
|