Almost done...this is the last group of any significant size!
Walton (William) was a 20th-century British composer in whose music Romanticism and modernity kiss. Everyone has probably heard his two coronation marches, Crown Imperial and Orb and Sceptre, neither of which is particularly to my taste. On the other hand, I may have mentioned before that his First Symphony (Walton wrote two of them) is among my favorite pieces. He also wrote concertos for piano, violin, viola, and cello; orchestral Variations on a Theme by Hindemith, the important oratorio Belshazzar's Feast, some sacred choral music, film scores (often for films based on Shakespeare), and a poetry recitation accompanied by chamber ensemble titled Façade.
Warlock (Peter), whose actual name was Philip Heseltine, was a Welsh-English music critic and composer. He composed under the Warlock name, which (like Samuel Clemens' "Mark Twain" pseudonym) has stuck with his work. Contrary to popular dramatizations of his life, there is no conclusive evidence that Heseltine had multiple personalities. He was a strange guy, and no mistake; deeply disturbed and afflicted by depression, he gassed himself to death at age 36. Nevertheless he left behind a body of very interesting music, much of it inspired by Renaissance and Medieval material. His best-known works include the Capriol Suite and The Curlew (a song cycle with chamber ensemble). He also wrote some popular carols and transcribed early English lute works for performance by modern instruments.
Weber (Carl Maria von) may have been the first "great" Romantic composer. Some of his operas, such as Euryanthe, Oberon, and particularly Der Freischütz, maintain an important place in the repertoire. He also left behind a one-movement piano concerto (Konzertstück), two clarinet concertos and other works featuring the clarinet, and a well-known piano piece called Invitation to the Dance.
Webern (Anton) stepped outside to light a cigarette and was shot to death by an American soldier, weeks after the end of World War II. This cut short the career of the most seriously committed and uncompromising member of Schoenberg's circle of twelve-tone serialist composers. I have actually listened to every one of Webern's compositions, a claim I can make about no other composer; but as his entire ouevre fits on 6 CDs, this isn't a titanic achievement. I remember listening to them in one weekend when I was on dorm-lounge-monitor duty in college. Several people passing through the dorm asked me what they had done to deserve it. Webern's works are mostly short, atonal, harshly dissonant pieces derived from mathematically strict musical formulas, with little to no development in the classical sense; most of their musical interest lies in the arrangement of unusual tone colors, and in the timing and intensity of contrasting blocks of sound and silence.
Widor (Charles Marie) is best known for the Toccata from his fifth symphony for organ, which is most often played faster than Widor wished. Though he wrote operas, a ballet, and assorted vocal and instrumental works, his main contributions to the repertoire are his ten organ symphonies, of which the fifth and sixth are the most famous.
Wieniawski (Henryk) was a brilliant Polish violinist who composed very few works. But these works include two important, and fiendishly difficult, violin concertos. His other works are chiefly of interest to violinists, including the invention of the so-called "Russian bow grip," a style of bowing conducive to previously unheard-of feats of virtuosity.
Willaert (Adrian) was a Flemish composer who moved to Venice and founded the "Venetian school" of which Gabrieli and Frescobaldi were heirs; this school of composition specialized in spectacular works of choral music in which separate groups of voices and instruments dialogued with each other from different locations, and which helped give rise to the Baroque era in music. If your tastes lean in the direction of Renaissance polyphony, you will probably run into his name a lot. You may also hear some of his music; he left behind hundreds of sacred and secular works. Apart from that, I have to mention him because, when I was a kid, I ran an AD&D character named Willaert (who was, incidentally, a bard). This activity wasted a staggering amount of my time; if I had spent half of it practicing, imagine where I might be!
Wolf (Hugo) was a Slovenian-Austrian composer whose orchestral Italian Serenade pops up occasionally on classical radio; he also wrote chamber, piano, and incidental music, and even three operas, of which Der Corregidor gets revived once in a blue moon. Really, his reputation as one of the near-great composers of all time rests almost entirely on his hundreds of songs, or Lieder (to use a little German lingo), for vocal soloist and piano accompaniment. A charismatic and deeply troubled man, he created a harmonic language of his own to express his pains and doubts, and in the process brought a peculiar kind of perfection to the art of expressing the meaning of words in music. Look for collections of his songs; if the "greatest hits" type of album doesn't appeal to you, you can sometimes find recordings of an entire song-cycle, such as the Spanisches Liederbuch, the Italienisches ditto, etc.