The Player Piano Group has published a few articles on the Billy Mayerl
Echo rolls over the years.  The definitive list of these rolls is being
compiled by John Watson in Norwich, member of both the PPG and the
Billy Mayerl Society (as per John Farrell's earlier response).

Echo was a small 'back-street' operator, apparently sold via corner
shops rather than music dealers.  Their numbering scheme is not clear,
so there is no good way of knowing when all their rolls have been
listed.

Technically, these rolls were not very well made - Mayerl himself wrote
an article in the mid 1930s saying how they had tried several different
ways of making the rolls - hand played directly, played at half-speed
and then reduced in length, a basic hand played roll with
embellishments, or even purely arranged.  He obviously never felt happy
with them. The surviving rolls bear out his concerns!

Musically, they range from poor to OK - only rarely hitting 'good'. One
of the problems must be that Mayerl was very young when these rolls were
made in around 1921, and his style hadn't matured.  The 78s he made (as
band pianist) at the time rarely have the piano audible to make any form
of comparison.

Hand-played rolls by known British dance pianists are very rare indeed -
only Echo and their successor, the Hand-played Music Roll Company, seem
to have made the effort.  Aeolian concentrated on classical pianists
when they recorded in London - only making one Mayerl Duo-Art roll. A
real missed opportunity.  They tried to make up by issuing a large
number of arranged Themodist rolls in the mid 1930s when Mayerl became
more generally known, but these rolls are quite rare.

Julian Dyer