Shouldn't a professional singer just memorise the lyrics?
Memorising works for a set you have played fifty times and not for a song written last week, a cover added this morning, or a session where the third verse keeps changing. A prompter frees the memory for phrasing and emotion instead of word order.
Recall and expression compete for the same attention. When a singer is hunting for the next word, the vibrato tightens, the timing stiffens and the performance flattens — usually in the exact bar that mattered most.
Broadcast solved this decades ago. Nobody expects a presenter to memorise a script, and nobody thinks less of the delivery for it.
No card required. Install the VST3, paste a lyric sheet, and record one take end to end before you decide.
In practice the opposite happens. Confident early passes make the song stick faster than anxious ones do.
Position the screen at eye level near the microphone and it reads as focus rather than reading.