Whenever I think of The Beatles, I think of them as being the first musical group to ever become just as successful worldwide as they were in their home country. Were there any pre-Beatles examples of this?
The nineteenth century was the first century when music truly became international with great composers and orchestras traveling across Europe and the United States. A good example is Johann Strauss II who while based in Vienna travelled to play in places as far afield as St Petersburg and Boston.