The composer’s nine-acre Roxbury estate has been put on the market for $3.25 million. Sondheim — whose influence on Broadway spans six decades and includes works like “Gypsy,” “Company,” “Sweeney Todd,” “Into the Woods” and “West Side Story” — lived in the Connecticut home for nearly 40 years. The antique house was built in 1792 and was a small farmhouse before Sondheim turned it into a three-bedroom compound, Graham Klemm, the listing agent said.