iTunes starts playing randomly after I have paused it

I have seen several posts about iTunes starting up and playing songs without any prompting, but my issue is slightly different. I know it is best to turn off a computer at least once per week and then turn it back on, which I do, but in between that time, I simply close my laptop when I am not using it and frequently leave the applications I am using running so that I can pick up where I left off when I turn it back on - usually never more than two applications at a time. Basically, if I am using iTunes and then pause it, close my Macbook, and then open it some time later, iTunes will sometimes "un-pause" itself and start playing the song again.

Note that I always manually pause iTunes before closing the laptop and it usually does not do this "un-pausing" thing immediately, but rather after I have been using the computer for a decent amount of time with no problem. I say "un-pause" because iTunes never boots up and then plays on its own. It only does this when already open. When this happens, I go to pause it and as soon as I go back to another application, before I've done anything beyond clicking the icon, it starts playing again. The only way to effectively stop it is by quitting iTunes. It's not that it is too difficult to quit iTunes when this happens, but it is still really obnoxious.

I have a storage capacity of 499.11 GB and I am only using about 70 GB. Below are the specs copy-pasted from "About this Mac." The only other music application I have is Spotify, which has a feature to access my local music files, but I rarely use it.

OS X El Capitan

Version 10.11.3

Macbook Pro (13-inch, Mid 2010)

2.4 GHz Intel Core 2 Duo Processor

8GB 1067 MHz DDR3 Memory

Macintosh HD Startup Disk

NVIDIA GeForce 320M 256 MB

Anyway, I have no idea if this is a common problem, if it is related to another application, or if I'm just being dense and missing something really obvious. Whatever the case, if someone could let me know how to stop this from happening, I would appreciate it.