I have > 30GB of music. It is on my RV and Home network HDs @ about 3mb per song this would be about 11 thousand songs (A WAG at best, not planning to count them). I have music from most generes from 1900 to present day except for the noisy crap I hear the "KIDs" listing to.
(Sorry younger generation but IMHO what you listen to is just noise to me but my parents told me that also at times. A Kid might be defined by me as anyone under 40 or even 50, LOL of course, so music is a generational thing and different strokes for different folks applies,)
We have several smart phones, tablets, PCs and thumb drives that have most music on them all as well as on the HDs. We also have > 200 ebooks and a variety of audio books on our digital devices. So we have all the stuff with us everywhere.
I have been recording music since the early 60s. Some are recorded on 7 1/2" reel to reel tape in analogue format and subsequently digitized from vynal 45s and LPs, 8 track, cassettes and sometimes radio and since CDs came out I have ripped them and downloaded from the web. (No pirate stuff, I own everything and use it for my private use)
We generally download audio books from libraries, it is mostly free if you have a library card, (using "Overdrive media") but we do have Kindle, Google Play, Sony, and Kobo Apps so we can get and read ebooks and listen to audio books through any device capable of playing MP3 and other audio formats,
I make up a variety of music playlists, my preference is CW, but I have musical sound tracks, old time rock, big bands, military bands and just about everything one can imagine. We like Daniel O'Donnell, Mary Duff, Jim Reeves, Dolly, Elvis, the Beatles, Patsy Cline and so many others singing songs we can understand the words or just easy listening music.
Can't imagine ever going back to any electrical/mechanical device, (except HDs for now) for carrying or playing music or even movies when solid state options are available. We have a lot of movies on our network also, still ripping my DVD movie collection. Have about 1000 DVDs to RIP yet. Thank goodness I do not have many in "blue ray" format, these files are huge. I have 4TB HD arrays right now at home and in the RV also but it is cheap to expand that capacity as required.
The same goes for books, we simply do not buy hard copy (READ PAPER) books anymore. If it is not available in soft copy, it gets a pass from us. Often we listen to audio books in the RV or listen to them while walking around. I get great enjoyment relaxing by the fire, or sitting outside reading or listening to music and often I do both.
Hardy ever watch live tv much anymore albeit we have 6 TVs in our house and can record and playback from any TV from the one PVR. I can take that PVR in the RV and play back recorded programs also.
So back to the question re playlists, I have so many I almost need a list for my playlists, albeit one can readilly sort by genre, song, artist etc and play accordingly, but most often I put the player on shuffle and get a random music selection from within the selected playlist.
Sorry, I was on a writing roll so to speak, but modern technology has made life sooo much easier for us to access and carry so much content in our pockets.