I think I found out why my MIDI keyboard wasn't connecting to my Sonar Home Studio 7 properly. Apparently, headphones or speakers need to be connected to the keyboard in order to get sound when connected to Sonar. I knew the jack needed to be a different size than regular headphones (like Apple) so I tried to find the size to the jack. Just my luck, it's not mentioned in the manual or on the keyboard itself. So, what size headphone jacks are normally used on MIDI keyboards? Any help will be greatly appreciated. Thanks!