Paula Abdul -
From First Live Show To AI Audition
Adam's first live concert experience was a Paula Abdul show. During his American Idol judges audition, he told Paula "I saw you when I was 10!". This puts the start of this arc in 1992, most probably July 28, 1992 when the "Under My Spell" tour stopped in Costa Mesa. You can find a recording of the Yokohama show from that year on YouTube.
This arc came Full Circle 5863 days later on July 17, 2008 when Adam met Paula Abdul face-to-face for the first time at his American Idol Season 8 audition. Counting against the TV broadcast of the audition's recording, it would be 6046 days until January 20, 2009. Either way, it is currently the second-longest arc we are tracking in our Chart (the longest one is over 30 years long!)
Watch the whole audition segment below, or skip to 2:20 to hear Adam mention his first concert experience to Paula. He clarified in later interviews that it was indeed his first live show, although he sometimes misremembered his age at the time...