The music publisher Giulio Ricordi allegedly heard him and advised him to undergo vocal instruction with Luigi Mancinelli, one of Italy's leading conductors.
According to some sources, Anselmi's first appearance on stage in an operatic role happened as early as 1896, when he sang Turiddu (Cavalleria rusticana) in Greece.
He appeared initially at the Teatro San Carlo, Naples, in late December of that year and, in 1901, at the Royal Opera House, Covent Garden, London.
His greatest triumphs, however, occurred in the cities of St Petersburg (often opposite Lina Cavalieri), Warsaw and, in particular, Madrid, where he even eclipsed the famous tenor Enrico Caruso in popularity.
Commentators often describe Anselmi (and his famous contemporary Alessandro Bonci) as being among the last exponents of the old bel canto method of Italian singing, which was largely supplanted in Italy during the early 1900s by a more forceful mode of vocalism associated with Wagner's music dramas and verismo opera.