I'm a big fan of baroque music that doesn't require a lot of thought and concentration. The equivalent of somebody like, say, James Taylor. He's soothing, and nice to have on while you're reading or something, because he isn't very demanding. He's going to Carolina and you don't need to know much else other than that.
Composers like Telemann are the same for me. They don't demand a lot of attention, they are soothing, they give me some nice background noise that helps me concentrate, but they aren't distracting. Bach cello suites incidentally, have the opposite effect. There's no way one can concentrate on anything else while they're listening to a cello suite. I know this to be true because I'm experiencing it right now. Let's just all pause and enjoy some Bach before we move on, shall we?
Ok, now that that's out of the way...
There are a handful of other composers who are pleasant and - dare I say, nice? - to have on when I don't want to pay attention to them, but still want something on that's not too distracting. Kind of like some of the baroque ornamentation around rooms in that when you first notice it, it's striking, but after a while it all starts to look alike, and while it sort of adds to the decoration, it kind of blends into the scenery after a while.
My new favorite composer like this is Christopher Simpson, which is a strikingly modern name. He was born around 1602 in Yorkshire. His father was a closet Catholic who ran a Catholic theater company (it was dangerous to be a Catholic sympathizer in 1606, but I can imagine that managing a Catholic theater company would be even worse).
He fought in the English Civil War, on the Royalist side, and, surviving the Siege of York, wound up as a tutor to the son of a wealthy family, and started composing. Most of his surviving work is for viol; he also wrote several books about viol technique, which saw a revival of readership as early music grew in popularity recently. Here's a playlist on youtube of Christopher Simpson music; and I highly recommend it for whenever you've got some concentrating to do, and want something not too taxing or distracting on in the background.