What Is The Name And Lyrics To The Orchestra Song That Goes, 'The Clarinet, The Clarinet, Goes Doodly Doodly Doodly Doo. The Horn, The Horn, It Sounds So Forlorn'?

The song you're thinking of is an Austrian folk song known as both The Instrument Song and The Orchestra Song. It featured on the soundtrack for the movie You've Got Mail, although the lyrics tend to vary from version to version as they song is originally in German.

The version in the movie was performed by by Jean Stapleton, Steve Zahn, Meg Ryan, Greg Kinnear and Heather Burns.
Lyrics to The Instrument/Orchestra Song The violins ringing like lovely singing. The violins ringing like lovely song. The clarinet, the clarinet, goes doodle doodle doodle doodle dat. The clarinet, the clarinet, goes doodle doodle doodle dat. The trumpet is braying, Ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta. The horn, the horn, awakes me at morn. The horn, the horn, awakes me at morn. The drums playing two tones. They're always the same tones. The drums playing two tones. They're always the same

Hope this helps!