I wonder if you know which song is playing on this video:
The song on violin is playing in the background of this video from time 0.30 minutes
I could identify this with Shazam. The song in question is Polonaise by the Japanese composer Shigeru Umebayashi. The song is from the original score to the Hong Kong movie 2046 which is a sequel to the quite well known movie In the Mood for Love.
To further add some information to the answer, here is some information about the Shigeru, quoted from Wikipedia:
Once the leader of Japan's new wave rock band EX, composer Shigeru Umebayashi began scoring films in 1985 when the band broke up. He has more than 40 Japanese and Chinese films to his credit and is perhaps best known in the West for "Yumeji's Theme" (originally from Seijun Suzuki's Yumeji), included in director Wong Kar-wai's In the Mood for Love (2000). Umebayashi scored most of Wong Kar-wai's follow-up film, 2046 (2004), and House of Flying Daggers. He is also the composer for the music of the first Serbian spectacle, Charleston & Vendetta. Umebayashi received the special "Tomislav Pinter Award" at Avvantura Film Festival Zadar (Croatia) in 2013 during his stay as member of the official Jury.