osmd-extended/src/MusicalScore/VoiceData/LinkedVoice.ts

export class LinkedVoice extends Voice {
    constructor(parent: Instrument, voiceId: number, master: Voice) {
        super(parent, voiceId);
        this.master = master;
    }
    private master: Voice;
    public get Master(): Voice {
        return this.master;
    }
}