Musiikkitalo, the home of the Finnish Radio Symphony Orchestra and the Helsinki Philharmonic, in a 2011 building by LPR Architects on the strip between Töölö Bay and Mannerheimintie. The main concert hall is shoebox-shape with vineyard balconies — a deliberate echo of the Berlin Philharmonie — and excellent acoustics.
Free open rehearsals are held on selected mornings; the website lists upcoming dates. The on-site café-restaurant is open all day. Walk in to look at the central foyer even if you do not have a ticket.