I'm not familiar with Soundtracks. I can tell you that Audacity would be a bad choice. It is audio editing software, but not set up for playing back finished tracks. Most of the track vendors have a piece of software for playback. The generally require either Windows or QLab. Some are very good. Others not. You are going to be hamstrug with the Chromebook requirement. If at all possible, you need to get a computer running Windows or a Mac for the task. If Mac, QLab is the industry standard for playback. For Windows I recommend Multiplay. Hope this is helpful.
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Kirk Longhofer
Theatrical Sound Design, Audio Production, Editing and Engineering
Systems Design and Consultation
www.technopraxis.orgkirk@technoprasix.org------------------------------