One well known pitch trap is the note that keeps recurring as the uppermost pitch in a melodic line – which then gets sung progressively flatter and flatter. Almost as if once you’ve sung the lower notes in between, you simply haven’t the energy to hike the pitch all the way back up there.
For example – in Sentimental Journey – Gon-na take a sen-ti-men-tal jour-ney. The third of the key starts the song and recurs on every other note, for all of the first phrase, and the start of the second.
Mi doh mi doh mi doh mi….And every successive mi seems to lose some pitch.
Drawing attention to this phenomenon really helps. I ask singers to think about singing each revisitation of the upper pitch slightly higher than the previous one.
Quite often if singers are aware of a trap they can fix it by just staying conscious. It’s a good idea to mark these repetitions in the original score during the learning process.
However, if I were doing Sentimental Journey with a chorus, I would have all the singers do the Onion Skin Stacking hand movements – so that they also had a physical movement to draw attention to the pitch trap.