Is listening to music while doing office work a good or a bad thing?

Very bad thing.

it depends on the music and the person listening to it, slow music relaxes the mind and helps the mind concentrate.
some people say the listening to loud music helps relieve stress during work.
So as i said depends on whose doing the work and what kind of work your doing.

I tend to get distracted by the lyrics, so I only listen to classical music while working!

If you're working on something like graphic designing, photo editing, etc. it won't be a problem. Any other work, NO ! It will distract you or take away your focus even. 

It depends on the music. Some music is educational and thus might be used by Academians. It depends if the music wil not distract you and others while at work.

There is a very old relation between music and work, you might have heard or seen people singing some song while doing work, which boost their energy and confidence level, music moves stresses and gives relaxation.

When I was working I wasn't aloud to listen to music, but if I had the opportunity, I would go for a soft, easy-going music without lyrics just to give you the feeling of an relaxed environment. The music that we prefer, can make us excited and our minds will travel far away from work. We don't want that, so light music is the answer. 

If it doesnt spoil your work like diverting your focus from work you can listen to it wearing headphones perhaps. Like those people who are graphic designers or content writers, for them the music blends well with work and its a good form of motivation.

In the field of Accounts its kind of disastrus to go for music option, well in case its a free time or you are stressed allot and you need a little break. So to best utilise that break of  5 or6 mins add a little relaxing soft music and the effect will be double.

Get back to work then.

As far as it helps somebody to concentrate in performing HIS /HER job better, it is good.

If it is distracting from work then it is bad.

it is not work behaivor