Four incredible songs to identify

All of them recorded with my iPod in the heat and turmoil of these August nights in various east-European capitals. All great hits, an easy task for anyone following the charts.

1.) http://picosong.com/uAZg
2.) http://picosong.com/uAZN
3.) http://picosong.com/uAZx
4.) http://picosong.com/uAZG

Grateful in advance.

3) https://www.youtube.com/watch?v=Xn676-fLq7I
4) https://www.youtube.com/watch?v=CSWQolyMZjw

1.) https://www.youtube.com/watch?v=mmW1t4Y5UtE

2. https://www.youtube.com/watch?v=3j4I0PqNzKE

or some of it´s remix.