I use Echonest in an application but I am restricted when I make several requests per minute.
I tried to contact Echonest but I do not have an answer, do you know what are the solutions to avoid this limitation of requests API ?
The Echonest API has partly been migrated to the Spotify API and the original API will be shut down.
See: http://developer.echonest.com/
Over the past two years, following Spotify’s acquisition of The Echo Nest, it’s become clear that rather than have two separate APIs with considerable overlap in features, it makes sense to migrate functionality and focus all of our future development on the Spotify API.
In doing so, there are a couple important dates you should be aware of:
March 29th, 2016 - We are announcing three new APIs (details below) and The Echo Nest API will no longer be issuing new API keys
May 31, 2016 - As of May 31st, The Echo Nest platform will no longer serve requests and developers will need to move over to the Spotify API.