When comparing Spotify vs cmus, the Slant community recommends cmus for most people. In the question“What are the best audio players for UNIX-like systems?” cmus is ranked 5th while Spotify is ranked 32nd. The most important reason people chose cmus is:
CLI makes Cmus clean, fast and minimalist.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Huge collection of music and fast access to newly released songs
Spotify has over 20 million songs and arguably the largest collection out of its competitors and usually has the fastest access to new music.
The Spotify desktop client allows local music files to be imported with the option of syncing with a mobile device which largely mitigates the issue of missing artists.
Pro Related artists
Helps to find new authors based on your previous picks
Pro Client's functionality can be extended via third-party apps
Spotify desktop client allows for third-party apps. They extend the functionality of Spotify and many of them offer new ways of discovering music. Noteworthy apps include Moodagent, Last.fm, Swarm.fm, ShareMyPlaylists, The Hype Machine, We Are Hunted, Shuffler.fm.
Pro Curated playlists
Public playlists on Spotify created by other people are great for finding new music.
Pro Has a free version
A free, ad-supported account allows streaming from an extensive library of music.
Pro Weekly Discover playlist uses a great algorithm
A playlist generated by Spotify based on your listening habits and released every Monday. The algorithm used by this playlist is great and stands out from its competitors.
Pro CLI only
CLI makes Cmus clean, fast and minimalist.
Pro Does not use a lot of memory
Cmus only uses about 15 MB. This is a very small and light media player, which is ideal for people with low end hardware.
Pro Good library structure
A lot of music players may act more like playlist viewers rather than a music library. cmus sorts by Artist > Year > Album.
Pro Works very well with tags from MusicBrainz database
cmus will factor in additional data from the MusicBrainz database while sorting. For example sort orders for arist or album, and the original release date for an album (in the case of a re-release).
Pro Fast
A lot of music players will be slow when starting if they have huge libraries, but CMus starts fast no matter the library size.
Pro Customizable keybindings for a personal experience
You can add keybindings for just about anything - including seeking (forward/backwards 1 minute, for example) which isn't supported by all music players.
Pro No mouse required
cmus does not require a mouse as it runs in the terminal
Pro Open source extensions and scripts
On GitHub you can find the official WIKI where there are a dozen extensions and scripts from color themes to a lyrics viewer and the ability to play YouTube songs.
Cons
Con Free account have lots of ads
If you hate commercials, you would buy Premium or go on using something else.
Con Discovery is terrible
The discovery algorithm is poor and does not learn fast enough. Not obvious how to train it.
Con Poor audio quality
There's a high range of bitrates and most of vary from average to bad.
Con No album art
cmus does not display album art
Con CLI only
No graphical interface is available for cmus. Everything is done through CLI (command line interface).
Con Difficult to use
Cmus uses odd keyboard shortcuts such as "C" to pause, "E" to add songs to queue, and "4" to edit the queue.