Can i search for a single song instead of tracks or album or playlist on echonest

Hi,

A Song entity in the API represents a particular piece of audio. The call you pasted is searching for unique pieces of audio matching that name that appear on Spotify; there are 5 of them, apparently, many of which have multiple Spotify tracks (because the same audio was released multiple times on complications, etc). The specific query you pasted gets just 1 of those 5. In that JSON you pasted, you can see it's reporting information on two different Spotify tracks:

{ 
  album_type: "other",
  album_date: "2006-04-18",
  foreign_release_id: "spotify:album:0GwGWIUoAdWiYQlLZfWim4",
  catalog: "spotify",
  foreign_id: "spotify:track:0wxzoFPm0eDAoWPaHpSYVW",
  album_name: "The Ultimate Collection",
  id: "TREPQBG147B6DD8467"
},

{ 
  foreign_release_id: "spotify:album:0tKmhD5LHaVkucUhMUpVn2",
  catalog: "spotify",
  foreign_id: "spotify:track:3uOoKYMLcj4JEo7rGZK89u",
  id: "TRWFNUQ147B6E30DBA"
}

The URI's listed under foreign_id for each should be usable through the Spotify web API (or just pasted into the searchbox in the Spotify app). Specifically, the URL you give -- https://play.spotify.com/track/4lEJYHkieQi5LfyFrN5bel -- seems to work fine for me.

To your other question, The Echo Nest API does not provide access to content, just information about it. You need an account with one of our partners who has licenses to actually distribute the audio. So yes, once you find something with our API, you'd need to use 7digital, spotify, or similar to actually stream it.

-Eli