Assalaamu alaykum. Does accidentally mixing worship and something haram cause disbelief? On this website, www.myreligionislam.com/detail.asp?Aid=6020 item number 37, it is stated, "To perform acts of worship or to sing Nasheeds (chants) accompanied by music causes disbelief because nasheeds are worship." The question is: what happens if one accidentally does so out of negligence; does such action bring one out of fold of Islam? Is there any dispensation to the rulings stated on the cited website? Thank You. Wassalaam.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger. 

Mixing an act of worship with something that is forbidden, such as music, is evil, but this does not necessitate issuing a ruling that the doer goes out of the fold of Islam as long as he did not intend to ridicule or mock the act of worship. Mixing supplications and religious songs (Anaasheed) and the like with music is not by itself an act of Kufr (disbelief), and it does not necessarily entail mocking the religion. However, what some Sufis do, such as taking singing accompanied by music as an act of worship and an act by which one gets closer to Allah, then this is an obvious evil.

Finally, we apologize for not commenting on everything on the site mentioned in the question because we are very busy with the great number of urgent questions from the visitors.

Allah knows best.