The music library at Lincoln Center in New York has a huge collection of music scores and resource books. You have to be there to appreciate it which is the point. You have to be there. "there".
I first visited the library when I came to New York to look at scores for my masters thesis. The score I needed to see was out of print - as is most music - and was not permitted to be sent via inter library loan. So I checked into what was the Empire hotel across the plaza (above the old O'Neill 'sBalloon) and walked in and there was a score that I had wanted to see for almost a year - right there on the shelf - just sitting there.
If you were a serious musician there was Patelson's music shop behind Carnegie Hall (also gone) or you could trudge down to Union Square and Carl Fisher the publisher but the outlets for music were few and far between. Moreover it was expensive - this music - with scores costing more than books and in a year's studying you might buy 100 of them.
The New York Philharmonic to their ever lasting credit is digitizing their entire music library and putting it up for free on their website. That is 180 years of performance music available to see and paw through. It isn't like holding the real thing but there it is and I can sit by my fireplace in the cold of night and look at these treasures all courtesy of this effort.
It may be hard to fathom but for a musician it is a wonderment and a gift. These are my books - my light reading so to speak and the Philharmonic has provided me with access to this world for the rest of my life.
Thanks.