I would like listen songs in swedish
Check out Eurovision, anything before 1999 will be either in English or in Swedish when it comes to the Swedish entries, specifically 1960-1963 all in Swedish for Swedish entries, then 1965 they chose to sing in English causing outrage, so the next year all songs were forced to be in one of the official languages of the country. Then 1973 to 1976 all songs could be in any language, so some chose to sing in English. Then 1977-1999 all songs where required to be sung in the official language of the country. 1999 is when English was allowed again, so now people sing in whatever language they want.
Sweden has some great progressive rock bands as well, if that's something you like. I particularly recommend the bands Kaipa (newer albums have English text, but the old ones are in Swedish) and Änglagård (all in Swedish).
I like Swedish dance music like September, Eric Saade and Therese Grankvist! Does anyone else know or recommend any other (commercial) Swedish dance artists?
Coming late to the post...I have found listening to Per Gessle (he's part of the duo Roxette) and his band Gyllene Tider to be very beneficial. Per has lyrics posted to all his solo songs and GT songs on his website. A lot of the songs are easy to understand and are great rock/pop songs.