Try: unison
At the same time.
The children were trained to recite the pledge of allegiance in unison.
unison or chorus
in unison
Try: unison
It's not a spell, as such, it is a technique called a Unison Raid, where two mages combine their spells as they cast them.
Unison in French is 'unisson'.
together
At the same time.
Yggdra Unison happened in 2009.
Unison Industries's population is 2,200.
Unison Industries was created in 1980.
The birds flew in unison.
Movement in unison is movement at the same time. For example you could do a dance move in unison, at the same time.
"Unison" can be either a noun (much more often) or an adjective. Example as an adjective: The fourth part of the oratorio is a unison anthem. Examples as a noun: The fourth part of the oratorio is sung in unison; how pleasant it is for a family to dwell in unison!
Banduria is tuned (from high to low): G (3 strings in unison) D (3 strings in unison) A (3 strings in unison) E (2 strings in unison) B (2 strings in unison) F# (1 string)