As already noted by the Accepted answer, the solution is
the Compact Disc, or CD.
Here's the explanation of all the clues in the riddle.
Click the magic button below to show them.
$\require{action}\require{enclose}\toggle{\enclose{roundedbox}{\text{ Show meanings }}\\
\small\begin{array}{l}
\\\text{Let me tell you a little about myself}
\\\text{Before I'm consigned to history's shelf.}
\\\text{I'm just in my 30s, though I feel so old.}
\\\text{It'll just take a minute for my tale to unfold.}
\\\
\\\text{Sometimes I think I have OCD —}
\\\text{I don't function well when I feel dirty,}
\\\text{And cats and dogs really give me fits}
\\\text{Cuz if I get scratched I might lose my --}
\\\
\\\text{It used to be I was everywhere.}
\\\text{The shiny new kid without a care.}
\\\text{Got my start in the music industry;}
\\\text{Was just sixteen when I got my Grammy.}
\\\
\\\text{Soon everybody wanted to copy me,}
\\\text{Ripping me off like some wannabe —}
\\\text{Hey, it's cool, imitation's just flattery}
\\\text{(Though the lawyers might tend to disagree)}
\\\
\\\text{But I wasn't content to just do one thing:}
\\\text{Had to do something new, had to spread my wings.}
\\\text{I mastered new stuff I hadn't done before.}
\\\text{Everyone knew I had so much more in store.}
\\\
\\\text{Started wearing new colors, started sporting new styles,}
\\\text{Gave photographers more chances to capture my smiles,}
\\\text{Started coming to my fans' houses regularly,}
\\\text{Opened new ways for them to interact with me.}
\\\
\\\text{The nerds all loved me; when they took a look,}
\\\text{I had something in common with their dear Thain's book!}
\\\text{They helped me launch yet a new career,}
\\\text{Though that's finally reached its end, I fear.}
\\\
\\\text{I held a lot of records in my heyday,}
\\\text{And it doesn't look like they'll be going away.}
\\\text{But time marches on, as it always will}
\\\text{And the last ten years have been all downhill.}
\\\
\\\text{I'm not as popular as I was in my prime}
\\\text{but I still make the rounds from time to time.}
\\\text{I'm a big part of some people's memories,}
\\\text{And they may call me up to aid in their reveries.}
\\\
\\\text{If you've patiently listened as this tale I told}
\\\text{You'll agree it's ok that I feel so old.}
\\\text{But I think we can both quite safely agree}
\\\text{That you now know my real identity.}
\\
\end{array}}
{\enclose{roundedbox}{\text{ Hide meanings }}\\
\small\begin{array}{lll}
\\\text{Let me tell you a little about myself}
\\\text{Before I'm consigned to history's shelf.}&\ &\textit{CDs often sit on a shelf.}
\\\text{I'm just in my 30s, though I feel so old.}&\ &\textit{Introduced in 1982.}
\\\text{It'll just take a minute for my tale to unfold.}
\\\
\\\text{Sometimes I think I have OCD —}
\\\text{I don't function well when I feel dirty,}&\ &\textit{CDs notoriously fail if dirty.}
\\\text{And cats and dogs really give me fits}
\\\text{Cuz if I get scratched I might lose my --}&\ &\textit{--"bits". Scratches are bad for CDs.}
\\\
\\\text{It used to be I was everywhere.}&\ &\textit{CDs were quite ubiquitous in the 90s.}
\\\text{The shiny new kid without a care.}&\ &\textit{CDs are indeed shiny.}
\\\text{Got my start in the music industry;}&\ &\textit{Originally developed for sound recordings.}
\\\text{Was just sixteen when I got my Grammy.}&\ &\textit{Technical Grammy Award, 1998.}
\\\
\\\text{Soon everybody wanted to copy me,}&\ &\textit{Digital format made for easy piracy.}
\\\text{Ripping me off like some wannabe —}&\ &\textit{Extracting audio tracks is called 'ripping'.}
\\\text{Hey, it's cool, imitation's just flattery}
\\\text{(Though the lawyers might tend to disagree)}&\ &\textit{RIAA aggressively litigated music sharing.}
\\\
\\\text{But I wasn't content to just do one thing:}&\ &\textit{Compact Discs have multiple formats now,}
\\\text{Had to do something new, had to spread my wings.}&\ &\ \ \ \ \textit{for Audio, Video, MIDI, CD-ROM, and more.}
\\\text{I mastered new stuff I hadn't done before.}&\ &\textit{Creating a CD's data image is called "mastering".}
\\\text{Everyone knew I had so much more in store.}&\ &\textit{CDs store data.}
\\\
\\\text{Started wearing new colors, started sporting new styles,}&\ &\textit{(See Note 1)}
\\\text{Gave photographers more chances to capture my smiles,}&\ &\textit{Photo-CD format.}
\\\text{Started coming to my fans' houses regularly,}&\ &\textit{Columbia, BMG etc. with Disc of the Month clubs.}
\\\text{Opened new ways for them to interact with me.}&\ &\textit{CD-i format for Interactive content.}
\\\
\\\text{The nerds all loved me; when they took a look,}&\ &\textit{CD-ROMs had impressive storage capacity.}
\\\text{I had something in common with their dear Thain's book!}&\ &\textit{(See Note 2)}
\\\text{They helped me launch yet a new career,}&\ &\textit{CD-ROM begat CD-RAM, CD-R, and CD-RW formats.}
\\\text{Though that's finally reached its end, I fear.}&\ &\textit{These have given way to DVD[-R[W]] and online streaming.}
\\\
\\\text{I held a lot of records in my heyday,}&\ &\textit{Records. Yup.}
\\\text{And it doesn't look like they'll be going away.}&\ &\textit{CD media is supposed to have a long lifespan.}
\\\text{But time marches on, as it always will}&\ &\textit{BMG stopped its mail-order Music Service in 2009;}
\\\text{And the last ten years have been all downhill.}&\ &\ \ \ \ \textit{sales of CDs are way down since 2004.}
\\\
\\\text{I'm not as popular as I was in my prime}&\ &\textit{MP3 players, smartphones, streaming services have taken over.}
\\\text{but I still make the rounds from time to time.}&\ &\textit{Rounds? Get it? I kill myself!}
\\\text{I'm a big part of some people's memories,}&\ &\textit{Many people have favorite music or photos on CDs}
\\\text{And they may call me up to aid in their reveries.}&\ &\ \ \ \ \textit{and play them to reminisce.}
\\\
\\\text{If you've patiently listened as this tale I told}
\\\text{You'll agree it's ok that I feel so old.}&\ &\textit{CDs definitely feel dated to most modern folk.}
\\\text{But I think we can both quite safely agree}
\\\text{That you now know my real identity.}&\ &\textit{Indeed.}
\\
\end{array}}\endtoggle$
Note 1
Compact Discs originally came only in silver. Now you can find them in pretty much any color. They also come in different styles (ones that look sort of like vinyl discs, for example), different sizes (mini CDs and "business card" size, as well as 74 and 80 minute capacity).
Moreover, different formats have different specifications, which are colloquially referred to by the color of the cover of their spec documents. Audio CD is defined by the Red Book, Super Audio is the Purple Book, CD-ROMs are the Yellow Book, and so on; in many cases, a single specification document now has extenstions that cover different styles (for example, Red Book covers Audio, and its extensions add CD-Text and CD-MIDI).
Note 2
Another document is also commonly called the Red Book - namely the Red Book of Westmarch, the specific copy called the Thain's Book in particular. Tolkien fans, often considered nerds, might well appreciate the Red Book nomenclature.
Fun Bonus Fact
Anyone old enough probably remembers those AOL CDs that everyone seemed to get in the mail, sometimes monthly, sometimes even more often. They made decent coasters, sure, and putting useless CDs like those in the microwave for 10 seconds with all the lights off is still really cool *, but man ... after the first half dozen or so showing up, it started getting realllllly tiresome.
Well, do you know how much AOL spent sending those out?
According to Jan Brandt, AOL’s former Chief Marketing Officer:
"Over $300 million :-) At one point, 50% of the CD’s produced worldwide had an AOL logo on it."
I thought you all should know.
_________________________________________
* If you damage your microwave doing this, don't blame me.
