INSERT Database

I have a system similar to Vagalume / Spotify
Where the artist has his page with the album list, and within the album, the songs ...
But there are music with several artists participating in the title, I would like to use for example:

Kid Ink - Ride Out (feat. Tyga , Wale , YG , Rich Homie Quan )

And each artist in the music title was linked and recorded separately in the database, as shown in the following image:

We're doing INSERT as follows:

if(empty($nin_s_feats)){
    $insert = "INSERT INTO musics (nin_s_artist, nin_s_music, nin_s_music_completed, nin_s_feats, nin_s_time, nin_s_album, nin_s_letter, nin_s_votos, nin_s_youtube, nin_s_traduc) 
               VALUES ('$nin_s_artist', '$nin_s_music', '$nin_s_artist $spacing $nin_s_music', '', ".$calc.", '$nin_s_album', '$nin_s_letter', '0', '$nin_s_youtube', '$nin_s_traduc')";
    $resultado = mysql_query($insert) or die ("nao foi possivel inserir");
    echo "<script> window.alert('Música: $nin_s_artist - $nin_s_music cadastrada!'); </script>";
} else {
    $insert = "INSERT INTO musics (nin_s_artist, nin_s_music, nin_s_music_completed, nin_s_feats, nin_s_time, nin_s_album, nin_s_letter, nin_s_votos, nin_s_youtube, nin_s_traduc) 
               VALUES ('$nin_s_artist', '$nin_s_music', '$nin_s_artist $spacing $nin_s_music (feat. $nin_s_feats)', '$nin_s_feats', ".$calc.", '$nin_s_album', '$nin_s_letter', '0', '$nin_s_youtube', '$nin_s_traduc')";
    $resultado = mysql_query($insert) or die ("nao foi possivel inserir");
    echo "<script> window.alert('Música: $nin_s_artist - $nin_s_music (feat. $nin_s_feats) cadastrada!'); </script>";
}

However, he only registers one participant, the others do not register.