As I was a tenor now, I delved up my copy of Unterrichtslieder from which I used to sing as a soprano, and decided I’d sing Frühlingslied D 398, by Franz Schubert. Die luft ist blau das tal ist grün
Then my voice deepened into the baritone range and as I had no sheet music for this Lied for middle or low voice, I moved on.
But listening to Dietrich Fischer-Dieskau singing it makes me want to acquire the sheet music for this song in middle or low setting.