Interactor 4.0.8 by Mark Coniglio and Morton Subotnick (review)

moments-the only reference to a natural sound world. It is a music that goes beyond our cultural barriers to perception, therefore it demands many listenings. This double CD is a must if one wants to understand and become familiar with the main body of early electronic pieces. It is important to know the roots and the first attempts to make music on tape, especially in the case of Koenig's music because he leaves many doors open for further research. ill. Software Fig. 2. An example of the 'Operator Select' window. The various classes of operators are listed in the top row, with the 'Conditions' class highlighted. The operators shown in the boxes are examples of 'conditional' operators. 'Send Note' operator will be invoked, performing a middle C (C3) on modem channel l (MI). Action operators are always true-that is, any additional operators after an action will be executed until a conditional operator tests false or the end of the statement is found. Figure 2 shows part of the 'Operator Select' window. The 'conditions' class of operators is highlighted and some of the conditional operators are shown, such as 'Test Note On' and 'Test Note Off'. These comments and the dialogue boxes for each operator are the primary on-line means offinding out what each operator does. Some pop-up 'help' windows for the operators would be a useful addition. Note that in Fig. 2 there are two classes ofoperators labelled 'Seq Play' and 'Seq Rec (ord) '. These operators access Interactor's eight simultaneous multichannel sequences. Documents can maintain up to 256 tracks of sequenced data. Any of the eight sequences can be assigned to any of the 256 tracks with the ease and flexibility characteristic ofthe language. Sequence volume, tempo and transposition are modified with custom operators . It is not possible, however, to route the output of the sequence through subsequent Interactor statements. One can route Interactor's sequencer output back to its input through Apple 's MIDI Manager, but this workaround is clearly incompatible with the elegance of the overall design. The language supports eight independent timebases, so that each sequencer can have its own temporal behavior. The timebases are also used by scheduling operators such as the 'Delay Timer,' which will postpone the execution of subsequent operators in a statement by some number of ticks in a timebase. Time is expressed in measures, beats and ticks, where 480 ticks equal one quarter note. This allows tempo to be varied while individual events maintain their relationship to an underlying metric structure. Timebases can be easily and flexibly changed with the appropriate operator, but the Interactor ment; whenever a conditional operator returns a false value, execution of the current statement is ended and the next one initiated. Collections of statements make up 'scenes' and scenes are organized into 'scene groups'. The highest level of organization in the language is the 'document ', which comprises up to eight active scene groups. Figure I shows a scene edit window , with one statement made of two operators, the basic building blocks of Interactor. Operators are used to evaluate conditions or execute actions . In the example statements, the first operator is a conditional operator looking for any MIDI 'Note On' message. The box below the operator is a comment showing the values of the operator's parameters. These parameters can be modified simply by double-clicking on the operator, which brings up a dialogue box wherein parameter values can be textually modified. In this case, whenever a 'Note On event' arrives, execution will pass on to the next operator in line, from left to right. Then a INTERACTOR 4.0.8 Mark Coniglio and Morton Subotnick , designers. Interactive Music Systems , P. O. Box 6727, Santa Fe, New Mexico 87502-6727, U.S.A. Tel: 213653 -7747. Reviewed byRobert Rowe, Dept.of Music, New York University, 35 w: FourthSt., Room 777, New York, NY 10003, U.S.A. Interactor is a graphic MIDI programming environment for Apple Macintosh computers. The environment was designed by Mark Coniglio and Morton Subotnick, and implemented by Coniglio. Interactor programs process several types of events, including MIDI, timing and Macintosh events. Statements in Interactor generally follow an 'if...