hi roy, thanks for your answer!
I saw on the github page that ofxTimeline hasn't been updated for a while, but from what i've seen it seems to be the only easy way to deal with timelines in OF. Would you have any other suggestion?
I've also tried to include ofxAudioDecoder after generating the project but that doesn't solve the problem, I'll try to generate a new project tomorrow and include ofxAudioDecoder in the first place.
Concerning the IDE, I'm using Visual Studio Community 2015 with the OF Plugin.