‘Rubber Duckie’ and other tunes land at Philadelphia Free Library, donated by Sesame Street’s Bob McGrath

Amid the Mendelssohn and Bach, tucked into the stacks of scores and other source material for music specialists, the Edwin A. Fleisher Collection of Orchestral Music has acquired a new star score: “Rubber Duckie.”

Scores and parts to the classic song are now in the Free Library of Philadelphia’s Fleisher — as are manuscripts to “The People in Your Neighborhood” and the Oscar the Grouch classic “I Love Trash.”

The materials are part of a cache that came to the Fleisher in more than 30 boxes from Robert Emmet McGrath — or as he’s known to anyone who’s ever loved Sesame Street — Bob. The actor and singer, who died in December at age 90, donated them to the Fleisher, which, next to the rest of the Fleisher’s very classical holdings, might suggest that one of these things is not like the others.

“There really is no one quite like Bob McGrath,” says Gary Galván, special collection curator for music for the Fleisher and other music collections at the Free Library.

It was Galván who picked up the phone at the Fleisher one day in 2016 to find McGrath on the other end of the line. McGrath and his wife, who lived in Teaneck, were downsizing in anticipation of a move. Would the Fleisher be interested in taking his materials?

“The moment he said ‘Bob from Sesame Street,’ I was suddenly a 5-year-old again and just thrilled,” said Galván, who is, in fact, a 59-year-old who watched Sesame Street at the show’s start in 1969. “I’ve spoken to a lot of famous people — you know, composers and performers and conductors — and I don’t think I’ve ever been as starstruck.”

Unknown to some was that McGrath parlayed his Sesame Street character into a substantial side career performing songs with symphony orchestras all over, amassing a collection of scores and parts to pieces from Sesame Street, Broadway, and other sources. They are generally arrangements commissioned by McGrath of songs written by others, says Cat McGrath, one of his daughters.

“The whole idea was to make symphonic music accessible,” said McGrath, who sometimes tagged along with her father on the road. “The minute he got on stage he encouraged the audience to stand up, clap, and sing along. This was not your average symphonic performance.”

She estimates that over 45 years, he performed live for a half-million listeners.

“The songs are universal,” she said. “Once you hear those chord progressions you reconnect with your childhood and all the fond memories of watching Sesame Street.”

McGrath had no prior connections to Philadelphia or the Free Library, but when he asked around about a home for his materials, various sources told him, “‘Oh, the Fleisher was the place to go,’” Galván said.

It was the place to go since, unlike many music libraries, its mission is to keep music in circulation so it can be heard. The Fleisher calls itself the largest lending library of orchestral scores and parts in the world, with 22,000 titles. It has a complete collection of the standard repertoire, plus many more specialized pockets of concentration. So far in the 2022-23 season, the Fleisher has circulated 8,356 scores and parts to 101 performing organizations in 11 countries. Philadelphia groups can borrow materials at no cost.

“The fact that we’re a living collection made a paramount difference” to McGrath, Galván said. “I mean, you look at the Library of Congress, they have more scores than we do.”

But they don’t lend out. “That’s what we do.”

McGrath’s donation arrived at the Fleisher in 2017. Other materials owned by McGrath went to the University of North Texas and Merit School of Music in Chicago.

Anyone renting from the McGrath collection will get not only the scores and parts, but also tips written onto the pages and in attached sticky notes.

“Get audience to quack/laugh first — then say ‘I think they are ready.’ Go!” says a note affixed to the front of the score to Jeff Moss’ “Rubber Duckie” by Boston Pops arranger Richard Hayman.

McGrath was best known for his Sesame Street persona, which he played from 1969 to 2016, but his musical background was extensive. He had degrees from two top music schools — the University of Michigan and Manhattan School of Music — and worked in show biz with figures like Mitch Miller.

“Here’s the slippery, slidy trombone,” says a notation for narration in a specially arranged version of Ravel’s Bolero intended to introduce the sections of the orchestra to classical-newbie audiences.

Bits and pieces of McGrath’s personality abound in these pages. And that gets back to the reason McGrath chose the Fleisher. Here, he knew, his materials would radiate out into the world and so, in a sense, would he.

So far, the McGrath collection has been loaned out out once — to the United States Marine Band, “The President’s Own” — which requested it for the performance that ended up being McGrath’s last, in 2018.

“It was great to be a part of that,” said Galván. “Because Bob got to see that we could get his things on the stage.”