# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# series.xrange.sonification.defaultInstrumentOptions.mapping.tremolo.speed

Map to tremolo speed, from 0 to 1.

This determines the speed of the tremolo effect, how fast the volume changes.