Songfacts®:

• The first single from Joe Satriani's Unstoppable Momentum album was initially earmarked for his Chickenfoot group. "I originally thought it would be perfect for Sammy Hagar to sing," said the guitarist. "I brought an unfinished version to the Chickenfoot lll sessions. We never got around to working on it, so, I happily put it back in my pocket for another day."
• Rewarding the song's meaning, Satriani explained: "It celebrates the coming of summer and the promise of adventure, fun and coming of age. It's a song about my high school memories lasting a lifetime and still giving me that good feeling when summer rolls around."
• The song title came from the wife of science fiction writer Robert Heinlein. Satriani explained to Digital Spy: "As the story goes, his wife was complaining about a bitter winter, and she said, 'I wish there were a door into summer.' He wrote a book with that title, although it was about something else altogether. Being a big reader of science fiction, I thought it sounded cool.
  
  "It's funny, because (The Extremist track) 'Summer Song' was going to be called 'A Door Into Summer,' but I changed it," he continued. "For some reason, I thought at the time that it was just too much. Also, I remember riding with one of the promo guys for Relativity Records, and he said, 'If I could just have that one summer song... ' That stuck in my head. I was reminded of the original title when John Cuniberti and I were doing this massive remastering of my catalogue. There it was on these boxes of tapes: 'A Door Into Summer.' I remember writing it years ago, thinking about that very first day of summer."
• The video is a behind-the-scenes look at Satriani and his band making their way to the Skywalker Sound studio, on the Skywalker Ranch in the Bay Area, setting up and starting the album recording process.