Looking for a restaurant or lounge to have a drink with classic music. Preferable a pianist or something like that.

I know about Nius on silom, but i am looking for an alternative.

Most of the major 5* hotels have a lounge where there is a pianist playing - usually soft pop, but I would guess that most of the pianists are classically trained and would play classical music if you so requested.

The "Living Room" at the Sheraton Grand on Sukhumvit is lovely for listening to soft Jazz musicians and I've seen a few talented piano players there. It's a tad pricey, but the set up is really, really nice. Low lighting....big plush sofas all around with a couple of glasses of wine.

360 on the top floor of the Millennium Hilton should fit the bill also.

i go with 360