Q: Why does iTunes open automatically on my computer?

=iTunes automatically opens=

Right click on iTunes in Dock and see if "Open at startup is checked"

See if a device is attached and "open iTunes when iPod is connected" is selected. https://discussions.apple.com/message/16483979#16483979 and May 2016: https://discussions.apple.com/message/30187456#30187456

Check for other iTunes preference settings that might cause this.

Hacks to stop Bluetooth speaker from starting iTunes -

http://forums.macrumors.com/showpost.php?p=19045335&postcount=4

LincDavis Aug. 2015 post - https://discussions.apple.com/message/28821151#28821151

May 2016 post: Check screen sharing - https://discussions.apple.com/message/30217767#30217767