You can't do it this way, you're $mp3 variable is actually: "http://www.pinchyandfriends.com/dl.php?mp3=*.mp3"
You have to solve it this way:
for mp3 in "title1" "title2" "title3"; do
wget "http://www.pinchyandfriends.com/dl.php?mp3=$mp3.mp3"
sleep 5
done
You should think how to obtain the mp3 names first.
Edit: Here's Your solution.
for album in $(wget -q -O- http://www.pinchyandfriends.com/ | egrep -o "/[0-9]+/[^/]+/"); do
echo $album
dl_uri=$(wget -q -O- "http://www.pinchyandfriends.com$album" | egrep -o '/dl.php[^"]+')
wget "http://www.pinchyandfriends.com$dl_uri"
done
This script gets the list of albums from the main page, then goes to the album page to fetch the download uri, and then uses wget to actually get the mp3