Hello Karolina! First I have to say that this is a really eye-catching photograph. You've chosen a perfect title. The blue hues give that "evening" feeling and the beautiful bokeh on the background creates a calm and "soft" atmosphere, just like a relaxing, tranquil song. I really like the contrast between the vibrant yellow and the deep blue tones- it makes it hard for the viewer to take his/her eyes from the photo. I also like the lightning. The only think that disturbs me a bit is that, on the top of the photo the last flower is a bit cropped. In my opinion, the photo would probably have more balance if there was a little blue part/line on the top as well. But that's not very important.
On the whole, this is an outstanding photograph. It's not another sunlit flower shot. With this shot, you've managed to reveal the beauty of nature through a whole new perspective. Congratulations!