This app was mentioned in 2 comments, with an average of 2.00 upvotes
Id recomend Star Music Player. Might not be extremely minimalistic, but it certanly fills the need for a good and useful widget. +It is a really good music player in my opinion.
That app was made by Star Music Studio, which looks like a Japanese company. It appears to be using the same font for its Star Music Player. I'm going to guess your sample is in the latin character set from a Japanese sans serif font, but I don't know which one that is.
Here's a much bigger sample of the font for your search.