Conversation so far:
What are Richard Strauss' tone poems?
A symphonic poem or tone poem is a piece of orchestral music, usually in a single continuous movement, which illustrates or evokes the content of a poem.
What was the name of one Richard Strauss's poems?
Aus Italien
What was the name of another Richard Strauss's poems?
Death and Transfiguration
Did Richard Strauss have any more tone poems?
yes
What was one of Richard Strauss's orchestral works?
An Alpine Symphony
Were Richard Strauss's works well received?
Richard Strauss's first tone poem to achieve wide acclaim was Don Juan (1889), and this was followed by other lauded works.
Are there any other interesting aspects about Richard Strauss's article?
James Hepokoski notes a shift in Richard Strauss's technique in the tone poems.

Question: What caused the shift?
Self-contained rewrite: What caused Richard Strauss's shift?