Alex Ross has a posting up about Giacomo Lauri-Volpi's 1934 recording of the Improvviso from Andrea Chenier. Here's Giovanni Martinelli's, from 1926; one of the great tenor's best. Note the breadth of the phrasing and the impassioned delivery.
And here's my favorite Lauri-Volpi recording. He had a heftier voice than one generally hears in this aria and it's an absolutely gorgeous recording, with marvelous rubato:
Looking around YouTube, I see that there's also an acoustic recording, from 1922, and a concert film from 1933.
These tenors both had unusually long careers. Lauri-Volpi, born in 1892, was still singing when Callas was in her heyday in the 1950s, and made some records into the 1970s. By the mid-40s, his voice had hardened and he usually sang forte. Martinelli sang opera until 1950, but I've never listened to any of the bootlegs after about 1941. However, there are some lovely or interesting concert records from the 1950s and even 1960s, including a genuinely beautiful "Winterstuerme," al'Italiano, from a radio concerto in 1957 and "Or son sei mesi," from Fanciulla del West, made with piano around 1962. He was an old man by then, and sounds it, but still.