This is from my husband:
I've been studying lighting design and have come across just about no information on proper angles (or range of angle) for adjustable accent lights (whether in ceiling or track). What I've found discussed is art lighting... 30deg. most common, 25deg. if wanting mild shadows from frames and/or bringing texture out on walls, 35deg for art work with heavy frames, so frames do not cause heavy shadows. I've found nothing but non-detailed descriptions/lighting plans for use as dining table task light and/or centerpiece accent, cross-bowl-aimed sink lighting, penninsula/island task lighting, accent lighting for objects on horizontal surfaces, etc. I've looked and called and written and have founjd so close to nothing, it's nearly the same. If you know about this topic, or know where detailed information about it is, I'd love to hear it.