Tomorrow marks the end of an era in reality TV as “American Idol” completes its 15th and final season.  Kelly Clarkson, who made  history when she became the show’s first winner, will be returning for the finale.

Clarkson also guested on “Idol” this past February 25th, singing her heartfelt and very personal song, “Piece By Piece.” While performing, she started crying, which caused me to tear up, too.

“Piece by Piece” brings to mind our fellow Baby Boomer Janis Ian’s 1975 soul baring “At Seventeen.”

Both songs take us to their inner sanctum of secrets—one about the treachery of teenager-hood and the struggle for acceptance, and the other about an emotionally damaged child who gets herself back together…piece by piece.

“At Seventeen” was a career high, an anomaly, a classic; “Piece by Piece,” which is just about to enter the pop charts Top 10, isn’t as as daring or as elegant as “At Seventeen,” but it packs an emotional wallop, just the same.

About that 15 years, from “American Idol” year #1, to now:

°  Clarkson’s become a bona fide star, with dozens of hits, is married and mother of an almost two-year old daughter and is expecting baby number two later this year.

°  American Idol has spawned numerous other talent contests.