in a train, from wien to stadt salzburg

I was in a train from Wien to Salzburg at the very first day in the newly Millennium year, almost seven years ago. I was with my friend, and chose to get on an empty compartment, which had two long seats for four people, in an Inter-City train at Wien. I slightly remember that it was almost three hour trip, and by the first an hour passed, we were only two in the compartment.
I forgot the name of the stop, where an elderly man came in our room. He firstly gave a glimpse into the room, and then said to us in German (maybe) if he could come in. We, of course, said "no problem", So, he just came in with a huge smile.
After the man sitting on an opposite seat to me, I realized that his clothes were coated with dust, and his smell was just like a dried straw. He just laughed, and said something in German, which I and my friend couldn't understand totally. We just inclined our heads. Then, he began to speak a broken German-English, though we hardly listen to. Finally, He began to sing a song.
At that time, I didn't know the name of the song, but felt that I surely used to listen to the melody someone sang somewhere.
Later, I found it was Stevie Wonder's "Music Of My Mind".
Here was in a train, from Wien to Salzburg, Austria.