From the Prayer Journal of Fr. Jack Tolley

You never pray alone. Somewhere in the world some person, some mass, some religious order,
some choir is singing with us every hour of every day. Even when we feel desolate and so alone.
Our prayers are also joined by choirs visible and invisible. This reality is very comforting for me -particularly when I have down days.
This reflection is from " Forward Day by Day," October 29, 2015. Author unknown.
Blessings, love, and hugs.
Fr. Jack.
 
Revelation 5:13. Then I heard every creature in heaven and on earth and under the earth
and in the sea, and all that is in them, singing,
"To the one seated in the throne and to the Lamb be blessing and honor and glory and might for ever and ever!"

Singing and chanting have been part of Christian worship since the earliest days of the church.
The apostles sang at the last supper. The psalmist believes that all creation sings to glorify God.
In Revelation we hear that angels, and indeed all living creatures, continually sing with full voice. 
During the Middle Ages, a belief circulated that all creation sings in praise of God unceasingly and
eternally. A great cosmic hum fills the air, resounding throughout the universe, vibrating forth from every atom.
Those chanting the divine office, the mass, any praise, or prayers, merely add their voices to the great chorus
going on already.  Therefore, you never pray alone. Even in the most isolated place or the most desolate state,
​ you are always joined by choirs visible and invisible.
Your voice merely joins their eternal song as invocation and petition, prayer and praise
rise up to the Almighty's attentive ear.