Chris Willman Senior Music Writer and Chief Music CriticIf there were an award to bestow for the most accomplished living American pop songwriter who never doubled as a recording artist, the frontrunner would almost definitely be Mike Stoller, 89, half of one of the most famous writing duos of all time, Leiber & Stoller. Even if the memory of Elvis Presley were completely wiped away, like the Beatles’ in that “Yesterday” movie, this pairing would still be in the history books and collective consciousness for “Stand by Me,” “On Broadway,” “There Goes My Baby,” “Young Blood,” “Kansas City,” “Love Potion #9,” “Yakety Yak,” “Charlie Brown,” “I’m a Woman,” “Ruby Baby,” “Is That All There Is?” and other numbers deeply embedded in pop culture from the mid-‘50s forward.