About the organs in the church, I've heard it may not be canonically correct to have organs, but I grew up in churches that had the choirs being led by the electric organ, and I really loved it.  I think a lot of people also like it very much.  And it made me learn the church hymns and fall in love with the church hymns. 
What the Greek Orthodox churches in this area of New York City used to do when I was growing up, is have the chanters chant in the first liturgy Sunday morning, and then the second liturgy on Sunday morning would be sung by the choir.
Also, it's a change from the chanting, which, by the way, I don't think the chanting is always done correctly.  For example, I've heard it said that it should be more lively, not like a slow… slow… slow ….drawn out chant.   And that's why I love the Russian chant.  It's very lively.
 
I'm sorry.  I don't mean to offend anyone who chants.  May God forgive  me and may He bless us all to love the Church and serve the Lord in ways that are pleasing to Him.
 
And it is very interesting to see that different countries sing or chant their Orthodox Church hymns in their own style and according to their culture.  It's beautiful.
 
Thanks, Father Seraphim and the whole congregation of St. Nicholas Mckinney, for sharing your Youtubes.  May Christ our God be with you all and bless you all and your church.