Midi Toolkit Ver 1.0. (22.May.2000)

The Midi toolkit consists of two objects:
1. Notes
2. Notetrack

notes object is a collection of tracks and is used to load and save a complete 
midi file.

notetrack object stores note events and makes it easy to access and modify
information.

A typical session would look like:

>> ns = notes('snd/stella.mid')           % Load a midi file

Track   Count   Len
1       832     159.253
2       546     159.244
3       464     159.247
4       187     156.136
5       546     159.250
6       1215    156.957

>> nt = ns{1};
>> nt(1:5)                   % List the first 5 events

Time    Dur     Pitch   Vol     Chan
----    ---     -----   ---     ----
1.09    0.62     70      76       0
1.09    0.57     63      85       0
1.09    0.55     74      93       0
1.09    0.55     67      89       0
1.09    0.56     58      73       0
159.25  ***************************

>> nt{1,3}                   % List events between t=1 and t=3
...

>> nt{1,3}.pitch             % Get pitches of events between t=1 and t=3
...
>> % Create a new track with same times with pitches transposed a forth up
>> nt2 = notetrack('t',nt{1,3}.t,'pitch',nt{1,3}.pitch+5)
...
>> % Same operation which uses original midi velocity and channel information
>> nt2 = nt{1,3}^4    %  Use -4 to transpose down
...
>> mj = [0 2 4 5 7 9 11 12]; % Create a Major (ionian) scale
>> nt1 = notetrack('pitch',60+mj,'t',linspace(0,5,length(mj)), 'len',6);
>> mn = [0 2 3 5 7 8 10 12]  % Create a minor (aeolian) scale
>> nt2 = notetrack('pitch',69+mn,'t',linspace(0,5,length(mj)), 'len',6);
>> nt_harm = [nt1 nt2];  % merge two tracks
>> nt_mel  = [nt1; nt2]; % Append The minor scale ater the major scale
>> save(nt_harm, 'sil.mid', 120); % Create a midi file with 120 bpm metronome

Note:
Saving and loading midi files depends on linux mex-binaries in 
@notes/private. 

notes2midi.mexlx   % Save
midi2notes.mexlx   % Load

(Binaries for windows95/98 have the extension dll).
If there are problems, you need to compile the c++
sources. Original c++ sources can be downloaded from
 
http:///www.mbfys.kun.nl/~cemgil/matlab/midisong4matlab.tar.gz

Listing of all methods in Notetrack

SUBSREF              Subscripted Reference to Notetrack Objects
SUBSASGN             Subscripted assignment
HORZCAT              Merges two notetracks
VERTCAT              Concatenation of two tracks in time
PLUS                 Shifts Note forward by delta time
MINUS                Shifts Note by backward by delta time
MTIMES               Scales durations and onset times by factor
MRDIVIDE             Scales durations and onset times by factor
MPOWER               Transpose the pitches by halfnote steps

NOTETRACK            Constructor (load)
SAVE                 Saves as a midi File 

PLOT                 Plot Function
DISPLAY              Display Function
LENGTH               Number of Note events
PLAY                 Plays a NoteTrack (needs an external program)

Author
Ali Taylan Cemgil,
SNN - University of Nijmegen, 
Department of Medical Physics and Biophysics
e-mail : cemgil@mbfys.kun.nl 
22-May-2000	 5:14 PM	ATC	Created under MATLAB 5.3.1.29215a (R11.1)

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This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.