The tenor is the highest natural male voice. Above that is the countertenor which uses an entirely different method of producing a sound. An operatic tenor might need a high C and might not, but he would seldom need to go above high C. They aren't known for their low notes. The sub-categories for tenor are generally listed:
Mozart tenor
Leggiero tenor
Lyric tenor
Spinto tenor
Dramatic tenor
Heldentenor
If there are more categories, we are ignoring them. I am now going to describe the sub-categories, but please be aware that the same singer may show up in different sub-categories. A role may also cross into more than one category. I have tried in selecting these examples to make sure that the singer is actually of the suggested sub-category.
Mozart tenor
A Mozart tenor is known for the beauty of his relatively light tone and for the perfection of his legato. Examples of Mozart tenor roles are Don Ottavio in Don Giovanni, Ferrando in Così fan tutte, Tamino in The Magic Flute, etc. The first film is Fritz Wunderlich singing "Dies Bildnis ist bezaubernd schön" from Die Zauberflöte.
Wunderlich is for some people the quintessential tenor. They will complain bitterly whenever someone doesn't sound like him. He is perfect for what he is singing here.
Our next example is Francisco Araiza singing "Dalla sua pace" from Don Giovanni.
Leggiero tenor
A leggiero tenor is basically a bel canto tenor (Rossini, Bellini, Donizetti, and early Verdi). They are expected to sing outrageous gymnastics and astounding high notes but aren't required to focus on their legato. They are the most likely operatic singers to receive a request for a bis--a repeat of the same aria. Leggiero is an Italian term that means between legato and staccato, or legato with small separations between the notes.
Examples of this Fach are Count Almaviva in The Barber of Seville (Rossini), Tonio in La fille du régiment (Donizetti), Elvino in La sonnambula (Bellini), Don Ramiro in La Cenerentola (Rossini), etc. And this is the essential performance for this Fach--Juan Diego Florez singing "A mes amis" from La Fille du Regiment.
Here is Javier Camarena singing the Prince from La Cenerentola.
Lyric tenor
During the bel canto the ideal sound for a tenor changed. Gilbert Duprez invented the sound of a tenor singing a high C "in chest." The public went mad for this intense, dramatic sound, and from that moment everything changed. Women as heroes disappeared, and the roaring tenor became the stereotypical operatic hero. Desire for the castrato sound evaporated.
Most tenors today are lyric tenors. They have lighter voices than the Fachs to follow, but their technique still follows the roaring tenor ideal. Examples of lyric tenor roles are Alfredo in La traviata (Verdi), The Duke in Rigoletto (Verdi), Lensky in Eugene Onegin (Tchaikovsky), Rodolfo in La bohème (Puccini), Werther in Werther (Massenet), etc. The first film is Pavel Breslik singing Lensky's aria from Eugene Onegin.
This is Luciano Pavarotti singing "che gelida manina" from La Boheme.
Spinto tenor
This Fach is between lyric and dramatic, just like the spinto soprano Fach. Examples are Manrico in Il trovatore (Verdi), Calaf in Turandot (Puccini), Hermann in Queen of Spades (Tchaikovsky), Radames in Aida (Verdi), etc. The greatest spinto tenor was probably Franco Corelli, here singing "Ah, si ben mio. Di quella pira!" from Il Trovatore.
For others the greatest tenor of all time was Placido Domingo who now sings as a baritone. Here he sings "Nessun Dorma" from Turandot.
Dramatic tenor
A dramatic tenor can get by without a high C most of the time. Usually this Fach is limited to Italian repertoire or Enée in Les Troyens (Berlioz). Canio in I Pagliacci (Leoncavallo), Dick Johnson, La fanciulla del West (Puccini), and Don Alvaro in La forza del destino (Verdi) are all examples of dramatic tenor roles, and all have been recently undertaken by the German tenor Jonas Kaufmann. The essential dramatic tenor role is Verdi's Otello in Otello which Jonas has not yet sung. Here is his "Ch'ella mì creda libero" from La fanciulla del West.
And here is Mario del Monaco singing "Dio mi potevi scagliar" from Otello.
Heldentenor
A German word has been coined to name a German Fach: Heldentenor, which means heroic tenor. A Heldentenor has a specific sound, powerful but bright and penetrating. I will try to find examples.
Florestan in Fidelio by Beethoven is probably the first dramatic tenor of either Italian or German type. This became its own category because of the large Wagnerian repertoire for this voice: Tannhäuser in Tannhäuser, Lohengrin in Lohengrin, Siegmund in Die Walküre, Siegfried in Siegfried and Götterdämmerung, Walther von Stolzing in Die Meistersinger von Nürnberg, Tristan in Tristan und Isolde, and Parsifal in Parsifal.
I have carefully selected these examples to represent the true Heldentenor sound. First is Lauritz Melchior singing The Prize Song from Die Meistersinger.
Here Ben Heppner sings "In fernem Land" from Lohengrin.
Last is Jon Vickers singing "Wintersturm" from Die Walküre.
Each category is a different voice and a different technique. My film selections are based on the quality of the performance and the sound of the voice and often do not include subtitles in English.
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I have become aware after writing this that it has been done before here. I don't think I agree with this. In particular I do not agree that a leggiero tenor and a countertenor are the same. Countertenors are singing falsetto and modern day leggiero tenors are not. I have separated dramatic tenor and Heldentenor because a Wagnerian tenor has a specific sound which the listener should become aware of. This sound is not heard in Italian repertoire where they still have dramatic tenors.