In political and common parlance, when people say 'work' they usually mean 'jobholding'.
Jobholding, at least outside the public sector, is really about doing tasks that contribute to a business, whether yours or someone else's, being able to make money in return for a monetary compensation known as a wage or emolument.
Yet there are non-jobholding forms of work: household or other kinds of chores, looking after children, caring for the sick and elderly, cooking, food shopping and so on.
Thinker Hannah Arendt distinguished labour, which she saw as being the servant to the necessities of the life cycle, e.g. farming and growing food and most things pertaining to biological survival, from work which, for her, manufactures objects or creations that lend permanence to the world, like building a house, a pencil or a spacecraft.
It could be argued that her concept of work included art works such as musical compositions, paintings, sculptures as well as literary books.
I have a wider understanding of work as being any activity that requires applying myself with an element of a resistance overcome.
That is to say when I'm not in the mood for an activity and yet do it, that feels more like work than leisure (what the Romans called necotium, non-leisure, as oppose to otium, leisure) whereas when I am in the mood for an activity, that feels more like leisure than work.
Thus the same activity can be leisure one day and work another day depending on whether it feels like a nuisance or not at a given time.
Thus jobs would always count as work for me because they would always be a nuisance, something I don't want to do, an encroachment on my leisure time.
Practicing piano could also be work depending on whether I'm doing it out of pleasure and enjoyment, in which case it would not be, or out of disciplined drudgery, in which case it would be.
It follows from this subjective approach to the concept of work that it is possible to work less simply by altering or at least influencing how you feel about a given task.
As Mary Poppins says to the Mr. Banks' children who are reluctant to tidy their room
"In every job that must be done, there is an element of fun. You find the fun and hop, the job's a game!"However it might be that my definition of work is too wide if one should be of the more puritannical opinion that work always denotes an activity that has to be done, whether for monetary reasons, keeping on top of chores of even because of creative fever, regardless of whether you want to or not.