Then my information is at best incomplete. I will have to do more research. Your correction is appreciated. If you could direct me to any sources, I would appreciate that as well.
Here are some resources:
On Qumran:
http://artistictheologian.com/2012/09/10/congregational-singing-and-the-dead-sea-scrolls/
Philo on the Therapeutae:
Then the President rises and sings a hymn composed as an address to God, either a new one of his own composition or an old one by poets of an earlier day who have left behind them hymns in many measures and melodies, hexameters and iambics, lyrics suitable for processions or in libations and at the altars, or for the chorus whilst standing or dancing…They all lift up their voices, men and women alike Then the President rises and sings a hymn composed as an address to God, either a new one of his own composition or an old one by poets of an earlier day who have left behind them hymns in many measures and melodies, hexameters and iambics, lyrics suitable for processions or in libations and at the altars, or for the chorus whilst standing or dancing…They all lift up their voices, men and women alike. (
De Vita Contempliva, 64 ff)
Philo on hymns and songs, which in context are clearly not canonical:
"And when they heard of the arrest that had taken place, and that Flaccus was now within the toils, stretching up their hands to heaven, they sang a hymn, and began a song of praise to God, who presides over all the affairs of men, saying, "We are not delighted, O Master, at the punishment of our enemy, being taught by the sacred laws to submit to all the vicissitudes of human life, but we justly give thanks to thee, who hast had mercy and compassion upon us, and who hast thus relieved our continual and incessant oppressions."
122 And when they had spent the whole night in hymns and songs, they poured out through the gates at the earliest dawn, and hastened to the nearest point of the shore, for they had been deprived of their usual places for prayer, and standing in a clear and open space, they cried out, 123 "O most mighty King of all mortal and immortal beings, we have come to offer thanks unto thee, to invoke earth and sea, and the air and the heaven, and all the parts of the universe, and the whole world in which alone we dwell, being driven out by men and robbed of everything else in the world, and being deprived of our city, and of all the buildings both private and public within the city, and being made houseless and homeless by the treachery of our governor, the only men in the world who are so treated. 124 You suggest to us favourable hopes of the setting straight of what is left to us, beginning to consent to our prayers, inasmuch as you have on a sudden thrown down the common enemy of our nation, the author and cause of all our calamities, exulting in pride, and trusting that he would gain credit by such means, before he was removed to a distance from us, in order that those who were evilly afflicted might not feel their joy impaired by learning it only by report, but you have chastised him while he was so near, almost as we may say before the eyes of those whom he oppressed, in order to give us a more distinct perception of the end which has fallen upon him in a short time beyond our hopes." (
Against Flaccus, 14).