RISC User Guitar
by Steve Hunt

This application implements a working guitar which may be played by moving
the pointer (plectrum) across the fretted strings. It creates realistic
sounds, and may be used both as a guitar tutor and as an accurate sound
source for tuning a guitar. Chord sequences may be saved and loaded from
disc.

Double-clicking on this application installs a guitar icon on the icon bar.
Clicking Menu over the icon will display the usual Info and Quit options.
Clicking Select over the icon will open the main Guitar window.


Tutorial
--------

The large white icon on the right of the window represents the neck of a
guitar; the top of the icon is the "tuning head" end of the guitar, and the
bottom of the icon is the "body" end. The first 9 frets of the guitar are
shown, and the black vertical lines represent the 6 guitar strings. Reading
from right to left (high pitch to low pitch) the strings are tuned to the
notes E,B,G,D,A,E. If (like me) you find it difficult to remember the notes,
try this mnemonic:

"Every Bad Girl Does An Essay"

The black "blobs" on some of the strings show where the strings must be held
down (or "fretted") by the fingers of the left hand to form a particular
chord shape. The "blobs" initially show the chord of C Major.

Try strumming the guitar as follows:

Move the mouse pointer until it lies to the left of the strings and low down
the neck. If your computer is equipped with RISC OS 3 the pointer will turn
into a hand holding a plectrum. Press and hold down the Select button, and
move the pointer from left to right across the strings - you will hear the
chord of C Major.

Experiment with your strumming and note the following effects:

  1. The strings only sound when the pointer crosses them with the Select
     button held down.

  2. The strings only sound if the pointer crosses them below the point
     where they are fretted.

  3. The strings sound equally well when strummed from right to left.
 
Now try changing the chord shape to Cmin6 by clicking Menu, moving right
over C and clicking Select over min6. Note that the top and bottom E strings
have a red cross on them - this denotes that they cannot be fretted
conveniently for this chord, and should not be played; in fact !Guitar will
prevent them from sounding should you strum them. Note also that the
writable icon in the box labelled "Chord" has changed to Cmin6 - this icon
always displays the name of the chord shape. Strum the chord and see what it
sounds like. 

We will now experiment with this chord by changing the position at which
some of the strings are fretted. You can do this by "dragging" the black
"blob" from the box labelled "Chord" and releasing it over one of the
strings. Try releasing it over the leftmost string at fret 4. Notice that
the red cross has disappeared and that a "blob" is now in position at fret
4.

Experiment with dragging "blobs" and crosses from the Chord box to the
guitar strings and note the following features:

  1. Releasing a "blob" over one that already exists causes the string to
     become open fretted.

  2. Releasing a cross over a string always positions the cross at fret 1
     regardless of where it was released.

  3. Releasing a cross over a string that is already crossed removes the
     cross.

  4. The writable icon in the Chord box always displays the name of the
     chord shape or a numerical representation of it.

  5. The frets can be cleared quickly by clicking over the Clear button in
     the Chord box, or by sel'ecting Clear from the menu.

You can enter numerical representations of chords (but not chord names)
directly into the writable icon of the Chord box - remember to press Return.
In this representation, numbers 1-9 indicate fret postions, 0 indicates that
a string is to be open fretted, and X indicates that the string should not
be played.

Try strumming chords and experimenting with the controls in the "Sound" box.
You can vary the volume in 3 steps, adjust the relative pitch of the guitar
in 1/8 semitone steps, and select one of 3 sustain levels. The Mute button
lets you "kill" the sound quickly - this is particularly useful when you
have Sustain set to Long.

Now let's suppose that we want to experiment with a sequence of chords. The
chords to be sequenced are displayed in the "Sequence" box at the left of
the window. !Guitar initially shows a sequence of GMaj-Emin-Amin7-D7th. You
can play these by strumming as normal and pressing F1 to step through the
chord shapes. Note, though, that !Guitar must have the input focus for F1 to
work. !Guitar allows you to specify up to a maximum of 16 chords.

Chord sequences can be specified in one of two ways:

  1. Drag the chord name from the Chord box writable icon and release it
     over the required sequence slot.

  2. Click Menu over the sequence slot and select the required chord. Note
     that in this instance the Menu options (including the Clear option)
     apply only to the sequence slot and not the guitar frets.

Experiment with the sequencer and note that any gaps in the sequence are bad
news - they force a step back to slot 1. Note too that the Clear button can
be used to quickly erase the sequence.

A sequence can be saved as a text file using the Save menu option (or F3) in
the usual RISC OS manner. A saved chord file can then be loaded by dragging
to the Guitar window. You can also edit the chord file using Edit or
DeskEdit, but note the following rules:

  1. Every chord must be on a new line.

  2. There must be no more than 16 chords.

  3. If you wish to specify one of the "named" chords, it must be identical
     in form to the Menu options. For example Amaj or F#min6, not AMaj or
     F#MIN6.

  4. If you wish to specify a "user" chord, it must be exactly 6 characters
     long and must comprise only of the characters 0-9 and X.


 RISC User 1993

