If you look for the oldest written songs, they’re invariably religious. The evidence used to establish meditation as religiously derived is sufficient to prove the same for song.
In fact, with the evidence at hand, I could just as easily argue that all religion derives from meditation. Secularly speaking, that is a simpler hypothesis than the inverse.
> all modern meditation comes from religious sources
I said modern organised practices of meditation come from religious sources. That caveat is as big as the difference between organised religion and sprituality, generally.
> The earliest written records of meditation come from the Hindu Vedas around 1500 BCE (Sharma, 2015). The Torah also contains a description of the patriarch Isaac going to “lasuach” in a field, a kind of Jewish meditation most likely practiced around 1000 BCE (Kaplan, 1985).
> I have seen no evidence of this.
That doesn't imply no evidence. In fact, there is tons of evidence that meditation originated from a religious context. It is not even controversial.
I have seen no evidence of this. Many religious practices involve meditation. But they also commonly involve song; it doesn’t follow that singing comes from a religious context.