If you want a service that'll build playlists based on the books you're reading, Muzify could be the way to go. This AI-powered system generates playlists based on the mood and tone of each book, and you can export them directly to Spotify. Muzify works on any device and lets you create as many playlists as you want, so it's a good way to get a little more out of your reading by linking literature and music.
Another option is Natural Language Playlist, an AI-powered system that can generate playlists based on the language you use to describe the music, cultural attributes and other factors. If you tell it you want a playlist that's "indie folk" and "wistful," it'll try to find something that fits the bill, even if that's a very narrow genre or theme.
If you want to explore music more broadly, PlaylistAI offers a range of options, including smart recommendations based on the time of day, custom playlists based on prompts you type in, and personalized recommendations for your favorite artists. It can link to Spotify and Apple Music, and you can try it with a free trial or subscription.
If you're looking for something more Spotify-focused, Playlistable can generate playlists based on your mood or your favorite artists. It can draw on your Spotify listening history to generate playlists, and it's got tools like Song Match and Artist Match to try to find the right music. It's got different pricing levels, including a one-time payment for 15 playlists, so it's a good way to explore music that's more to your liking.