Wadsworth Longfellow and Frank Alden had both worked for H. H. Richardson, as this house attests. Built of ochre sandstone with bands of brownstone, the Abbot House resembles, among others, Richardson's Glessner House (1885) in Chicago. The relieving arch over the front entrance and the massive scale of ashlar block emphasize the weight and surface texture of the wall. The original building was L-shaped, with two towers, dormers, and chimneys counterpointing the horizontal feeling. Lines from “The Poet's Tale: Lady Wentworth” by Henry Wadsworth Longfellow evoke the mood of this design by his nephew's firm: “Gables and dormer-windows everywhere/And stacks of chimneys, rising in the air,—/Pandeaean pipes, on which all winds that blew/Made mournful music the whole winter through.” The Longy School of Music purchased the building in 1937 and commissioned a concert hall and library addition in 1968 that filled in the ell. The bland walls of the new section are built of brown brick with brownstone trim, similar to the Roman bricks and stone used for the low wall that surrounds the property.