undfont.instrument(audioContext, 'acoustic_grand_piano'),
            Soundfont.instrument(audioContext, 'orchestral_harp'),
            Soundfont.instrument(audioContext, 'acoustic_bass'),
            Soundfont.instrument(audioContext, 'flute'),
            Soundfont.instrument(audioContext, 'tuba')
        ]).then(([piano, harp, bass, flute, tuba]) => {
            instruments = {
                'chords': piano,
                'arpeggio': harp,
                'bass': bass,
                'top': flute,