A good starting point would be Spotify's "Study" or "Focusing" genre, which contain a variety of curated playlists made by Spotify editors.
Since you tagged this question with classical-music, you could also take a look at something like "Study: Classical Concentration"
And if you want something completely different, I suggest looking at Lo-Fi Beats that ...
The tune is "American Patrol", a march written by Frank White Meacham in 1885 incorporating both original musical themes by Meacham and melodies from American patriotic songs of the era. Glenn Miller's Orchestra recorded a swing version of the march in 1942 (arranged by Jerry Gray).
Here's the march played by the United States Marine Band.
In the Journal of the Royal Musical Association Vol. 136, No. 1 (2011), pp. 33-71 there is an article "Handel and Homosexuality: Burlington House and Cannons Revisited" by Thomas McGeary. I can't find the full text of the article, but the abstract probably contains enough information:
It has been claimed that Burlington House and Cannons, the homes of the ...