I generally visit the Cow after work and have a pint or two with the lads. The Contented Cow is a non-smoking English pub on the waterfront.
Several nights a month there is live music--which I tend to shun, but many of my friends really enjoy the music nights. One crowd-pleaser is a group called Bonnie and the Clydes.
One word of warning. Stay away from the food. It is called pub grub and believe me, grub is a perfect description. If you are hungry, I'd suggest running upstairs to the delightful Chapati Restaurant for some Indian food.
This is as exciting as things get in the evenings in Northfield. Quiet town. Quiet pace of life. Every once in a while the college kids will come downtown to drink it up in the bars, but even then the scene is rather subdued. No raucus bar fights or loud parties. Which is good, because I like to be in bed by about 10:00 p.m.