Amarok vs Clementine

Amarok contains the following features:
Built-in equilizer
Built-in lookup of songs and artists (Amarok will display Wikipedia articles or lyrics of songs that it can find.)
Ability to add online playlists or streams, which is great for online radios such as soma or di.fm.
Supported by Cinnamon Desktop media widget.
Built-in iPod and iPhone support.
Built-in MTP and USB support.
Built-in music services for Ampache, gpodder.net, Jamendo, Last.fm, Magnatune, Amazine Music, MP3tunes, and podcasts.
Amarok can configure, add, and import scripts.

The design of Amarok does not resemble most other music players. It's definitely in a class of its own.

The ability to assign global keys to move from one song to another, rewind X seconds, advance X seconds, etc. Other players do not have that feature.

You can search for songs in the playlist... without adding a filter that prevents you from seeing the other songs. That way you can find e.g. the song that has been played before House of the Rising Sun. Using other players you can not search for songs in the playlist without hiding the songs that are not looked for.

Clementine features competent tag managing for all music files, be it album art or just simple text entries.

Clementine is easy to get up and running with lyrics, equalizer, online info, etc., within minutes after installation.

A fork of the 1.X line of Amarok, Clementine favours usability over design trends.

Organizes your music folder based on the tags of your library.

There is a very good remote app for Android. The app lets you do a lot: from the usual volume controls to checking the lyrics on your phone. You can even download the songs from Clementine onto your phone.

Clementine includes support for services such as Ampache, Google Play Music, Spotify, and many internet radio stations such as Jamendo and Icecast. It's also possible to search all available sources (local and online) at once, as well as mixed content playlists.

There is a built-in equalizer with many presets from genre-specific rock, pop, and party, to experiences such as large hall and live. You can also tweak it yourself and name your own preset.

Clementine gathers the user's listening data to use for smart playlists. Clementine uses your listening history to play music similar to the music you play most - which typically is music you will like but maybe haven't discovered yet.

Users can format any of their music files to a different format with Clementine's built-in format conversion tool.

Fetches lyrics from several lyric providers.

Unlike some other players in this list, Clementine doesn't seem to go unresponsive in the Ubuntu 16.04 system and looks really good with options for Visualization too.

Clementine allows the user to move and organize audio files easily. Some examples include the following:

• It's easy to find a specific album song (find artist, select album, select song).
• It's easy to add songs to a playlist and queue the songs.
• It's easy to rename files from their metadata (artist, album, song number, etc).
• It's easy to add cover images.
• There are options to find duplicates, untagged songs, etc.