Confused meaning

"I wrote that song as a homage to Deep Purple. And kind of got that out of the way, and then I could do whatever I wanted to with the rest of the album. It’s not as great as the one on ‘Rising’ -the album is nowhere near as good as ‘Rising’ -but it had a magic to it, and it was two very different sides. And whether they intended “Stargazer” and “A Light in the Black” to be equal songs or not, or to be a continuation story hat’s how we’ll always interpret it. " please explain what the author means starting from the sentence " Its not as great as the one on rising ..." ? What album had magic to it and two different sides ? How did they interpret stargazer and a light in black ? Thanks a lot !