Focus/energy boost: A few days ago I stumbled across this YT channel of isochronic tones music like this. That and my over-the-ear-headphones seriously improved my ability to focus in spite of other people talking/working around me. After-lunch playback speed increased to 1.25x gave an energy boost without making the music sound weird.
Fun fact: If there are work tasks you don't want to do, procrastinating those tasks while this music is playing just makes you even more focused on not wanting to do them.