Roll20 has a Jukebox feature to play music and sound-effects in a game. Ideally you should set the individual tracks you choose to about halfway in volume, not so loud that they will drown GM and player talk, and then move the Master Volume in the GM Settings (Gear icon on the top right of a Roll20 table) to maximum only in dramatic moments. Tabletop Audio is represented in the Jukebox track sources. They have very decent 10-minute music-loops to set the mood in many genres of campaign. But their website also features SoundPads, which operate independently of Roll20. It generates a soundboard where the GM can mix sound effects on the fly, and then "broadcast" it by giving players a link to a web-page (provided they can open a window independent of Roll20). Here is the SoundPad for "cyberpunk" cities: <a href="https://tabletopaudio.com/future_city_sp.html" rel="nofollow">https://tabletopaudio.com/future_city_sp.html</a>
