Everyone on the basic tenets of Islam is a Muslim
Bukhari, Hadith 50
Hadith of Jibraeel
“Tell me about faith.” The Prophet(Peace and blessings of Allah be upon Him)said, “Faith is to believe in Allah, His angels, His Books, His Messengers, the Last Day, and to believe in providence, its good and its harm.”
Misguided even rectified their act back in the day... as the door was open to all... till one from within started takfir on ones within and mended with the kuffar.
While even back then some sought verdict on what they said and did...
At-Tawbah
9:65
"If you question them, they will certainly say, “We were only talking idly and joking around.” Say, “Was it Allah, His revelations, and His Messenger that you ridiculed?"
Ones partaking in al wala wal bara doing concerts to reflect their modernity to open vulgarity while Palestine burned...