Find tracks by Audio Features and Album Type

[benjabby]

I can use the recommendations feature to generate a list of songs for given genres that satisfy Audio Feature criteria, in my case I need a list of tracks that have min_instrumentalness=0.6. I can get 100 tracks per request this way. 

However I also need only tracks whose album is album_type=SINGLE

If I were to manually filter through the max 100 results I can get per request, its entirely possible none of them could be tracks with album_type=SINGLE so I would have to make another recommendation request. Rather than 100 tracks per request I would only be able to get 100*p per request where p is the probability of a track's album being of type album_type=SINGLE which likely quite small.

I can't do anything with the search API, as both album_type and audio features are not included in search parameters. To find only tracks where album_type=SINGLE with the API, as far as I can only do so per-artist. Because I need to retrieve (relatively) random songs from different artists, that would mean one request per track, which is massively impractical.

Is there any way to retrieve a selection of songs (i.e track information) that only come from singles, matching the audio features criteria I need using few requests? In theory if I can get 100 tracks per recommendation request or 50 per search request I should be able to do the same to find the types of tracks I need but I don't know if it's possible.

Any help would be appreciated, thanks.