Wireless MIDI test using a wireless network connection from PC to smartphone. I'm using the Roland Sound Canvas iPhone app as the sound module of the MIDI file being played on my PC. The only thing wired on my iPhone is a cheap, tiny speaker but you can use a Bluetooth speaker for your sound output. Sound is captured through a video camera hence all the noise in the house is heard during filming.
Update: This is an old video. This was taken during when Roland Sound Canvas iPhone app was fairly new. The Windows version was released a month after (if I'm not mistaken). I'm doing it the other way around now. MIDI player on an iPhone and my Laptop as the sound generator.