When I play a recording of a concert that's been divided into tracks and add the tracks in consecutive order to the playlist, I get a small but noticeable gap in the audio playback between the tracks. I want the tracks to play consecutively without any gap (the crowd's clapping should be continuous without any interruption).

I went to Settings > Configure Amarok > Playback. When I place the cursor over the Volume section, I get "Current Phonon backend does not support volume fading" and that box is greyed out. Is this the setting that I need to change?

I'm running Version 2.9.71 on Ubuntu Server 18.04 with a xfce GUI Desktop.

Thanks!

Yes, you need to use a backend that supports gap-less playback, not all Phonon backends support this, but unfortunately not many backends are available in most distributions.

I installed gstreamer, but I don't know how to change the Phonon backend. Google hasn't been of any help.

You need to install the package "phononsettings", then run it from a konsole. In my distribution the package to install was called "phonon4qt5settings".

Since Audio is now run directly via pulseaudio the backend settings were removed from the System Settings to avid people mingling in the audio settings too much, as it was most of the time unnecessary and usually rather counter-productive.

Phononsettings isn't available for Ubuntu18 - "dependency is not satisfiable libphonon4qt5-4". I've asked for help on the Graphics and Multimedia forum. Maybe someone there knows.

Well, this depends on the distribution, no use asking elsewhere in the forum, if you use an outdated Plasma/KDE version there is no way around this but to upgrade. Works perfectly fine here.