Work songs are a method to regulate joint or several labour. In joint labour it allows all labourers to pull together. In both joint and several labour it allows the labourers to regulate their pace of labouring and thus their exertion and exploitation.
In contrast mechanisation is used by capitalists to smash existing labour regulations (Thompson, “Time…” Past & Present [futon: libcom.org]). This allows capital to regulate labour by the pace of the machine. Even when workers sing to attack machine labour, their songs are not as fast as the real machine:
Poverty poverty knock/
My loom is a saying all day
Versus a power loom’s cacophonous rapidity: https://youtu.be/-T2vrJ6haK0 at 1 minute plus