Because modus operandi is an established phrase in English and there is nothing to suggest Photek intended it to be seen as Latin (like when all or lots of other tracks on the release have purely Latin titles), I would keep the English capitalisation for that title.
Thanks for creating this thread @ulugabi. I think that @mfmeulenbelt has nicely summarised why Modus Operandi is the more appropriate way to capitalise the title. Do you still have any doubts about how to capitalise the recording title or can we revert edit #75578534?