I answered this previously but cannot find my post. Perhaps this happened in a Baptist church in the south, but not likely in a Southern Baptist which is a particular denomination of Baptist. There are several other Baptist denominations.
Having been a member of several Southern Baptist Churches as I moved from one town to another and changed membership to the Southern Baptist church near me. and having been a Southern Baptist for 64 years, I have never heard of either singing or speaking in tongues being a part of the worship service. I also have not heard of it being practiced in private worship but I cannot know about that.

The Baptist I know tend to believe that on the Day of Pentecost in the book of Acts a miracle occurred which enabled the hearers to understand the witness of the apostles, especially named is Peter, though there were people of various nations gathered there to celebrate Pentecost. (A Jewish feast day comemorating the Law being given to Moses.)

However, knowing quite well and being related to some Pentecostal Christians and attending services often as a guest I am convinced of the sincerity of people "speaking in tongues" though I do not know exactly what it is.
It seem likely to me it is abandoning control of the sounds one makes and allowing a spontanious flow of sounds to emerge in wordless spiritual praise of God.

However, I know nothing except the fact of my own existence. I consider it impossible to know anything else.

I do have strong faith in a number of things including a true and living, loving God and the guidance of his Holy Spirit.