So my physics department has 4 faculty members. I've had only one research project which I worked on this summer. I'm going to ask my research advisor for a LOR and I think it will be fairly strong. The problem is that he is also the professor I've had the most classes with. I'm not sure who else to ask for my other two LORs. I've only had one class with my academic advisor even though he is doing research in the field I will want to do research in graduate school. Another professor I've had a few classes with, but I don't think a LOR from him will be as strong as the one from my research advisor. I could also ask one of the math professors since one of them is very fond of me and has good things to say about me since I did well in his class and then eventually graded the same class the next year for him. Does anyone have any opinions on who I should ask? Another option is to ask one of my music professors since I am doing a physics/music double major, but I don't think that it would be very helpful.