From the Massachusetts Treasurers manual;

Town Meeting:
Town meeting possesses the legislative authority of a town. A town meeting may only be called pursuant to a warrant, a document that notifies the inhabitants of the time, place and subject matter of the meeting. The warrant is normally issued by the selectmen; however, the voters of a town may petition a meeting. (39:10) Each town must hold an annual town meeting in February, March, April, or May. (39:9) Town meeting may be delayed by a vote of the selectmen, but all business must be completed on or before June 30th. That portion of the town meeting providing for the election or certification of officers and ballot questions may not be delayed. (See IGR 86-202 in the Addendum for more information.) A town may also hold as many additional special town meetings as necessary to consider and conduct town business. Town meetings are open, with all registered voters eligible to participate, unless a community has adopted a representative town meeting form of government pursuant to Ch. 43A §2. Town meeting is responsible for all appropriations (40:5) and for the enactment of all bylaws. (43B: 13) It acts on behalf of the town to accept local option statutes, unless a statute specifies another mode of acceptance. (4:4) Town meeting may authorize the selectmen to sell town land (40:3) or to act as water and sewer commissioners, assessors, etc. (41:21) The town meeting also decides whether to establish certain town boards (such as trust fund commissioners under 41:45)

Finance Committee :
Every town with an equalized valuation exceeding one million dollars must, and any other town may, legislate the mandatory election or appointment of a finance committee (also called an advisory, appropriation, or prudential committee). The terms of committee members may not exceed three years, although the size and composition of its membership may vary. In all cases, the finance committee has the responsibility to consider all municipal questions for the purpose of making a report to town meeting. Furthermore, unless a provision of a town's bylaw gives the responsibility to the selectmen, the finance committee must present a budget at the annual town meeting. Even if that ultimate responsibility lies with the selectmen, the finance committee possesses an important role in budget preparation. The committee should review estimates provided by the various municipal departments and formulate them into spending recommendations for inclusion in the town meeting warrant. Furthermore, the finance committee has the power to approve transfers from the reserve fund, a contingency fund usually appropriated as part of the annual budget, to departmental budgets for extraordinary or unforeseen occurrences. (40:6) Overview and Legal Basis of Municipal Finance in Massachusetts Page 1-13 The finance committee is the official fiscal watchdog for a town. Finance committees were established to permit a representative group of taxpayers to conduct a thorough review of municipal finance questions on behalf of all citizens. 

Jeff Bennett