How can you deal with this scenario? Say you have to keep focused on the project but you simply hate the artist, the music, the material, and the music. 
Can you have good judgment working with music that sucks for you?
i don't know kung tama ang isasagot ko. pero actually if you own or do recording dapat talaga music lover ka. any kind of music actually. in my case i have a rock band pero sa recording mas type ko actually ung ibang music eh. ex. ng mga clients ko are soloist na sopranos at tenors. meron din akong rinecord na 8 voice harmony with 1 guitar. nag record na din ako ng grand piano with solo flutist. tapos i did a project para sa isang school na religous ang songs. and actually i enjoyed it.
kaso tanung mo eh ung song you hate eh no? well siguro since nandyan ka talaga sa work na ganyan you have to be profesional or pwede mo siguro tangihan at sabihin na di mo kabisado ang music nila and tell them na baka di ikaw ang best person o studio na gumawa nung music na iyon.
pero ako i really enjoyed recording other kinds of music. parang ang dating sa akin eh from WAR (rock) to peace (clasical, kundiman, musical)
pareho yan sa ganito na way of thinking: just because I say I like eating - the very act of eating, because it gives me pleasure, enjoyment, and whatever else - does not mean I will eat anything just because I happen to like eating. ever hear of shooting yourself in the foot with a blanket idea? analogously, just because I like food doesn't mean I can say, without a doubt, that I will like and love any kind of food. travelling has shown me that what we consider a delicacy is gross in some parts of the western world but there is also stuff they eat - and this goes for other parts of europe and asia as well - that is enough to make me gag because I never really simply thought that that was edible at all, much less a delicacy!
now, just like working with other genres of music, I will try anything once (or several times) just to give it the benefit of the doubt because, heck, it might taste good. I am a staunch believer in having varied experiences but there are genres that I just don't like; I am entitled to it because I am human and most people have preferences. but as far as the food analogy goes, there are things, animals, objects, and concoctions that are just plain weird, gross, nasty to even think about eating. if you ever get a chance to visit Thailand's open air markets, taiwan's midnight markets, and Vietnam's local "exotic delicacies," try tasting what you see but don't ask what it is.
