Attention Parrotheads: Jimmy Buffett and his Coral Reefer Band are bringing their margarita-filled beach party to Lansdowne Street next month for a special smaller-venue show at the House of Blues on Aug. 11. The concert is all-ages, and tickets go on sale Thursday, July 28 at 10 a.m. (limit four per customer). If you miss out, don’t fret: Buffett will play the Xfinity Center in Mansfield on Aug. 20.