The song is at 128 BPM (beats per minute) and the melody is played in E major. The arpeggio, bass and chords are however in the C# minor. These are the same notes, but the most played note is basically different. Avicii has combined synths together with orchestral instruments like the cello and the piano. I am not going that deep into details, but with the pictures below you should be able to get pretty far.
This is the intro synth which is an arpeggio:
There is a slight slide in the notes if you have noticed.
This is the melody together with the chords:
The chord progression is i-III-VII-VI.
And this is the bass:
It is basically the same as the lower part of the chords.
And here you can listen to the song:
So, basically this is my first song. I hope you like it. Feel free to request songs, so I can remake them.