o ignee spiritus laus tibi sit
qui in timpanis et citharis operaris
This is plainly translated who is working in (the instruments of / in the sound of) timpanies and citharas,
but I thought this in timpanis et citharis may be instrumental.
So I checked L&S and Gildersleeve.
in L&S for in + abl. there was no definition of by means of,
in Gildersleeve for the preposition in, too, there was no such definition, and the section for ablative of means (401) had no example of the use with in (only, in Note 1., erudire in + abl. was mentioned).
But in L&S for operor there was a sample sentence with in + abl. which obviously means instrumentally.
http://www.perseus.tufts.edu/hopper/tex ... y%3Doperor
B. In partic., in relig. lang., to serve the gods, perform sacred rites, to honor or celebrate by sacrifices
“sacra refer Cereri laetis operatus (= sacrificans) in herbis,” Verg. G. 1, 339;
What do you think ?
Though this is a different additional question,
in L&S operor under the article (b). With dat., to bestow pains upon a thing; to devote one's self to, be engaged in or occupied with a thing (mostly poet. and in post-Aug. prose):
there is a sample with in + abl..
“in cute curandā,” Hor. Ep. 1, 2, 29:
I wonder if this is the meaning used in in timpanis et citharis.