Until 1903, Lennartsson was a pharmacist-in-training, then he started to study voice at the Stockholm conservatory. He made his debut in 1908 at the Royal Opera House Stockholm, first in a tiny role in L'étoile du nord, then as Nando in Tiefland. He stayed at that theater for his entire (short) career, until 1924, all the time singing both comprimario and main roles (comprimario roles only in his last few years): Rodolfo (his favorite part), Almaviva, Ernesto, Don Ottavio, Arturo in Lucia di Lammermoor, Nicolai's Fenton, Nadir, Lenskij, Roderigo in Otello, Spalanzani, Shujskij, Marouf, Don Curzio. A few times, he tried himself in heavier roles like Turiddu, Erik and Max, with limited success. He left a great number of records.
Anton Bieber has provided the Gounod recording and label scan: thank you!
I wish to Daniele Godor for the recording.