The second ad shows a young man starting a new band. He enlists the help of Siri to find a place to buy a guitar, learn the chords to a couple of songs including "London Calling" by The Clash. Siri also shows the kid how to play a Bm9, and puts a possible name for the band, "Migraine Headache" on a list. The kid has his personal assistant send an email to a pair of his groupies to tell them that his band will be playing the garage that night. Lastly, this poor deluded kid asks Siri to address him as "Rock God" and Siri says she will comply.
Oh, if you were wondering how Siri responded so quickly to the questions in the commercials, when in real life you find yourself waiting endlessly for a response, it is all done through the magic of television. In the fine print at the end of the ad, you might have caught the phrase "sequences shortened".