Mrs. Murphy’s Pub, the new restaurant on Salem Street in Medford Square, begins a full weekend of live music with a performance by the Fiddle Pete Duo — Peter R. Subramanian on fiddle and Noah Kelly on guitar — playing traditional Irish music. Following will be Ethan Robbins on Friday, Feb. 28, at 8 p.m.; Katie O’Brien on Saturday, March 1, at 8 p.m.; Robbins again at noon on Sunday, March 2; and Temple Mountain on Sunday afternoon at 4.