Saturday marks the 2009 season’s Open House, one of the festival’s most popular traditions, as Music@Menlo invites the community to get a behind-the-scenes look at the festival. The day’s activities begin with a Q & A Coffee with Artistic Directors David Finckel and Wu Han (8:30 a.m., Welcome Center). Following masterful performances on Friday evening of the Mendelssohn Octet and other works, the festival’s nonpareil artist roster gears up for the season’s next concert program: visitors to Menlo School can sit in on open rehearsals (on this day only!) for Concert Program III, “Midsummer Night Dreams.” 2009 Visual Artist Theo Noll offers his unique insight into his craft at the noontime Cafė Conversation in Stent Family Hall, whose walls are graced by a collection of his exquisite paintings. Also, in addition to open Chamber Music Institute coachings throughout the day, the festival’s youngest musicians get their chance to shine in the afternoon’s Koret Young Performers Program (2:00 p.m., Martin Family Hall). Open House culminates in Encounter III, “The Grand Tour,” led by the world’s leading Mendelssohn authority, R. Larry Todd (7:30 p.m., Martin Family Hall; tickets required).