Subsections


Grooves

Grooves, in some ways, are MMA 's answer to macros ... but they are cooler, easier to use, and have a more musical name.

Really, though, a groove is just a simple mechanism for saving and restoring a set of patterns and sequences. Using grooves it is easy to create sequence libraries which can be incorporated into your songs with a single command.

Creating A Groove

A groove can be created at anytime in an input file with the command:

DefGroove SlowRhumba

Optionally, you can include a documentation string to the end of this command:

DefGroove SlowRumba A descriptive comment!

A groove name can include any character, including digits and punctuation. However, it cannot include a space character (used as a delimiter), a colon ``:'' or a '/'.6.1

In normal operation the documentation strings are ignored. However, when MMA is run with the -Dx command line option these strings are printed to the terminal screen in LATEX format. The standard library document is generated from this data. The comments must be suitable for LATEX: this means that special symbols like ``#'', ``&'', etc. must be ``quoted'' with a preceding `` \''.

At this point the following information is saved:

Using A Groove

You can restore a previously defined groove at anytime in your song with:

Groove Name

At this point all of the previously saved information is restored.

A few cautions:

To make life (infinitely) more interesting, you can specify more than one previously defined groove. In this case the next groove is selected after each bar. For example:

Groove Tango LightTango LightTangoSus LightTango

would create the following bars:

  1. Tango
  2. LightTango
  3. LightTangoSus
  4. LightTango
  5. Tango

Note how the groove pattern wraps around to the first one when the list is exhausted. There is no way to select an item from the list, except by going though it.

You might find this handy if you have a piece with an alternating time signature. For example, you might have a 3/4 4/4 song. Rather than creating a 2 bar groove, you could do something like:

Groove Groove34 Groove44

For long lists you can use the ``/'' to repeat the last groove in the list. The example above could be written:

Groove Tango LightTango LightTangoSus /

When you use the ``list'' feature of GROOVEs you should be aware of what happens with the bar sequence number. Normally the sequence number is incremented after each bar is processed; and, when a new groove is selected the sequence number is reset (see SEQ, discussed here). When you use a list which changes the GROOVE after each bar the sequence number is reset after each bar ... with one exception: if the same GROOVE is being used for two or more bars the sequence will not be reset.6.2

Another way to select GROOVEs is to use a list of grooves with a leading value. This lets you select the GROOVE to use based on the value of a variable ... handy if you want different sounds for repeated sections. Again, an example:

Set loop 1 // create counter with value of 1
Repeat
  Groove $loop BossaNovaSus BossaNova1Sus BossaNovaFill
  print This is loop $Loop ...Groove is $_Groove
  1 A / Am
  Inc Loop // Bump the counter value
RepeatEnd 4

If you use this option, make sure the value of the counter is greater than 0. Also, note that the values larger than the list count are ``looped'' to be valid. The use of ``/''s for repeated names is also permitted. For an example have a look at the file grooves.mma, included in this distribution. You could get the same results with various ``if'' statements, but this is easier.


Extended Groove Notation

In addition to only loading a new groove by using the name of a GROOVE you can also set the specific file that the GROOVE exists in by using a filename prefix:

Groove stdlib/rhumba:rhumbaend

would load the ``RhumbaEnd'' groove from the file rhumba.mma file located in the stdlib directory. In most cases the use of an extended groove name is only required once (if at all) since the command forces the file containing the named groove to be completely read and all grooves defined in that file will now be in memory and available with simple GROOVE commands.

Extended groove names, in just about all cases, eliminate the need for the USE command. For a complete understanding you should also read the PATHS section, here, of this manual.

Important: The filename to the left of the ``:'' is a system pathname, not a MMA variable. As such it must match the case for the filename/path on your system. If, for example, you have a file casio/poprock1.mma and attempt to access it with GROOVE Casio/Poprock1:PopRock1End it will not work. You must use the form GROOVE casio/poprock1:PopRock1End. The case of the data to the right of the ``:'' is not important.

When using an extended name, you (probably) only need to use the full name once ... the entire file is read into memory making all of its content available. For a, contrived, example:

  1. Assume you have two files, both called swing.mma. One file is in stdlib; the other in mylib. Both directories can be found in PATHLIB.

  2. stdlib/swing.mma defines grooves ``g1'', ``g2'', ``g3'' and ``gspecial''.

  3. mylib/swing.mma defines grooves ``g1'', ``g2'' and ``g3''. It does not define ``gspecial''.

  4. Near the top of your song file you issue:

    Groove mylib/swing:g1

    The file mylib/swing.mma is read and the groove ``g1'' is enabled.

  5. Later in the file you issue the command:

    Groove g2

    Since this groove is already in memory, it is enabled.

  6. Next:

    groove Gspecial

    Since this groove is not in memory (it wasn't in the file mylib/swing.mma) MMA now searches its database files and finds the requested groove in stdlib/swing.mma. The file is read and ``Gspecial'' is enabled.

  7. Now you want to use groove ``g1'' again:

    Groove g1

    Since the file stdlib/swing.mma has been read the ``g1'' groove from mylib/swing.mma has been replaced. You, probably, have the wrong groove in memory.

To help find problems you may encounter managing multiple libraries, you can enable the special warning flag (see here):

Debug Groove=On

which will issue a warning each time a GROOVE name is redefined. You must enable this option from within a file; it is not available on the command line.


Overlay Grooves

To make the creation of variations easier, you can use GROOVE in a track setting:

Scale Groove Funny

In this case only the information saved in the corresponding DEFGROOVE FUNNY for the SCALE track will be restored. You might think of this as a ``groove overlay''. Have a look at the sample song ``Yellow Bird'' for an example.

When restoring track grooves, as in the above example, the SEQSIZE is not reset. The sequence size of the restored track is adjusted to fit the current sequence size setting.

One caution with these ``overlays'' is that no check is done to see if the track you're using exists. Yes, the GROOVE must have been defined, but not the track. Huh? Well, you need to know a bit about how MMA parses files and how it handles new tracks. When MMA reads a line in a file it first checks to see if the first word on the line is a simple command like PRINT, MIDI or any other command which doesn't require a leading trackname. If it is, the appropriate function is called and file parsing continues. If it is not a simple command MMA tests to see if it is a track specific command. But to do that, it first has to test the first word to see if it is a valid track name like Bass or Chord-Major. And, if it is a valid track name and that track doesn't exist, the track is created ... this is done before the rest of the command is processed. So, if you have a command like:

Bass-Foo Groove Something

and you really meant to type:

Bass-Foe Groove Something

you'll have a number of things happening:

  1. The track Bass-Foo will be created. This is not an issue to be concerned over since no data will be created for this new track unless you set a SEQUENCE for it.

  2. As part of the creation, all the existing GROOVEs will have the Bass-Foo track (with its default/empty settings) added to them.

  3. And the current setting you think you're modifying with the Bass-Foe settings will be created with the Bass-Foo settings (which are nothing).

  4. Eventually you'll wonder why MMA isn't working.

So, be very careful using this command option. Check your spelling. And use the PRINTACTIVE command to verify your GROOVE creations. A basic test is done by MMA when you use a GROOVE in this manner and if the sequence for the named track is not defined you will get a warning.

In most cases you will find the COPY command detailed here to be more robust.

Groove Aliases

In an attempt to make the entire groove naming issue simpler, an additional command has been added. More complication to make life simpler.

You can create an alias for any defined GROOVE name with:

DefAlias NewAlias SomeGroove

Now you can refer to the groove ``SomeGroove'' with the name ``NewAlias''.

A few rules:

Groove aliases are a tool designed to make it possible to have a standard set of groove names in MMA usable at the same time as the standard library.

There is a major difference between a groove alias and the simple act of assigning two names to the same groove. Consider this snippet:

...define some things ...
Defgroove Good
Defgroove Good2

You now have both ``good'' and ``good2'' assigned to the same set of sequences, etc. Now, lets change something:

Groove Good
Chord Voice Accordion
...

Now, the groove ``good'' has an accordion voicing; ``good2'' still has whatever the old ``good'' had. Compare this with:

...define some things ...
DefGroove Good
DefAlias Good2 Good

Now, make the same change:

Groove Good
Chord Voice Accordion

By using an alias ``good2'' now points to the changed ``good''.

AllGrooves

There are times when you wish to change a setting in a set of library files. For example, you like the Rhumba library sounds, but, for a particular song you'd like a punchier bass sound. Now, it is fairly easy to create a new library file for this; or you can set the new bass settings each time you select a different GROOVE.

Much easier is to apply your changes to all the GROOVEs in the file. For example:

Use Rhumba
Begin AllGrooves
Bass Articulate 50
Bass Volume +20
Walk Articulate 50
Walk Volume +10
End
...

The ALLGROOVES command operates by applying its arguments to each GROOVE currently defined. This includes the environment you are currently in, even if this is not a defined GROOVE.

You can use the command with or without a track modifier:

AllGrooves Volume p

or

AllGrooves Chord Octave 5

Everything after the directive is interpreted as a legitimate MMA command. A warning message will be displayed if the command had no effect. The warning ``No tracks affected with ...'' will be displayed if nothing was done. This could be due to a misspelled command or track name, or the fact that the specified track does not exist.

If you want to ``undo'' the effect of the ALLGROOVES just import the library file again with:

Use stdlib/rhumba
Groove Rhumba

or remove all the current GROOVEs from memory with:

GrooveClear
Groove Rhumba

In both cases you'll end up with the original GROOVE settings.

A few notes:

Deleting Grooves

There are times when you might want MMA to forget about all the GROOVEs in its memory. Just do a:

GrooveClear

at any point in your input file and that is exactly what happens. But, ``why'', you may ask, ``would one want to do this?'' One case would be to force the re-reading of a library file. For example, a library file might have a user setting like:

If Ndef ChordVoice
Set ChordVoice Piano1
Endif

In this case you could set the variable ``ChordVoice'' before loading any of the GROOVEs in the file. All works! Now, assume that you have a repeated section and want to change the voice. Simply changing the variable does not work. The library file isn't re-read since the existing GROOVE data is already in memory. Using GROOVECLEAR erases the existing data and forces a re-reading of the library file.

Please note that low-level settings like MIDI track assignments are not changed by this command.

Groove aliases are also deleted with this command.


Sticky

In most cases the method used to save and restore grooves works just fine. However, you may want a certain track be invisible to the groove mechanism. You may find this option convenient if you creating a ``click track'' or if you are using triggers (see here) across different grooves.

Setting a track as STICKY

Drum-Testing Sticky True

solves the problem.

The command takes a single value of ``True'' or ``False''. ``On'', ``1'', ``Off'' and ``0'' may also be used. The only way a sticky track can become un-sticky is with a command like:

Drum-Testing Sticky False

You can set the sticky bit from a TRIGGER command as well. The results are the same.

Note: Sticky tracks are not deleted with the SEQCLEAR command.

Library Issues

If you are using a groove from a library file, you just need to do something like:

Groove Rhumba2

at the appropriate position in your input file.

One minor problem which may arise is that more than one library file has defined the same groove name. This might happen if you have a third-party library file. For the proposes of this example, lets assume that the standard library file ``rhumba.mma'' and a second file ``xyz-rhumba.mma'' both define the groove ``Rhumba2''. The auto-load routines which search the library database will load the first ``Rhumba2'' it finds, and the search order cannot be determined. To overcome this possible problem, do a explicit loading of the correct file. In this case, simply do:

Use xyz-rhumba

near the top of your file. And if you wish to switch to the groove defined in the standard file, you can always do:

Use rhumba

just before the groove call. The USE will read the specified file and overwrite the old definition of ``Rhumba2'' with its own.

This issue in covered in more detail here in this manual.



Footnotes

... '/'.6.1
The '/' and ':' are used in extended names.
... reset.6.2
Actually, MMA checks to see the next GROOVE in the list is the same as the current one, and if it is then no change is done.
Bob van der Poel 2017-03-25