way to count number of attached audio files?

Just wanted to add my current code incorporating zirafa's answer in case it might assist someone else looking for a similar solution. It works well. Thanks.

/**
*   EXAMPLE THEME FUNCTION OVERRIDE TO DISPLAY ONE XSPF PLAYER
*   Theme used if multiple files are attached
*/

function garland_audio_attach_list($nids, $teaser = FALSE) {
  drupal_add_css(drupal_get_path('module', 'audio_attach') .'/audio_attach.css');

//if statement below counts number of files in playlist: returns extended player if > 1, slim player if = 1
if (is_array($nids) && count($nids) > 1) {
  // generate an XSPF extended player for this playlist
  $player = audio_get_players('name', variable_get('audio_feeds_default_player', 'xspf_extended'));
  $playlist_url = url('node/' . arg(1) .'/xspf', NULL, NULL, TRUE);
  $output .= "<strong>Audio samples:</strong><br>"; 
  $output .= theme($player['theme_xspf'], $playlist_url);
  $output .= "<br>";
} else {
  // generate an XSPF slim player for this playlist
  $player = audio_get_players('name', variable_get('audio_feeds_default_player', 'xspf_slim'));
  $playlist_url = url('node/' . arg(1) .'/xspf', NULL, NULL, TRUE);
  $output .= "<strong>Audio sample:</strong><br>"; 
  $output .= theme($player['theme_xspf'], $playlist_url);
  $output .= "<br>";
}  
  return $output;
}

I need a little more info on the above, please. I'm now working with a separate template for the node type which includes the audio players as defined above. I have this in my node-type.tpl.php file, but it only partly works:

print garland_audio_attach_list($nids, $teaser = FALSE)

I do get a player, but it appears on every node, whether or not there are audio files attached, and the switch I have configured to choose between the extended and slim players no longer works. Only the slim player gets displayed (although it does play multiple selections if they are in a playlist). I guess I need another way to count attached files in the if statement? Any ideas?

Zirafa, thanks for the reply. That helped a lot. I'm not sure if this is what you meant, but I changed my node template line to:

print garland_audio_attach_list($node->audio_attach, $teaser = FALSE)

which brought back the switching effect I was after, but the slim player was still appearing on all nodes. I'm guessing this was because (according to the devel module) the audio_attach array seemed to be present on all of my nodes even if the array was empty (i.e. no files attached). I solved this by wrapping the player generation/switching code in another if statement which checks to see if the array has anything in it first. I don't know how clean/efficient this is, but it's working so far. Included below for the record:

function garland_audio_attach_list($nids, $teaser = FALSE) {
  drupal_add_css(drupal_get_path('module', 'audio_attach') .'/audio_attach.css');
if (count($nids) > 0) {
  if (count($nids) > 1) {
  // generate an XSPF extended player for this playlist
  $player = audio_get_players('name', variable_get('audio_feeds_default_player', 'lacymorrow_xspf_player'));
  $playlist_url = url('node/' . arg(1) .'/xspf', NULL, NULL, TRUE);
  $output .= "<strong>Audio samples:</strong><br>"; 
  $output .= theme($player['theme_xspf'], $playlist_url);
  $output .= "<br>";
  } else {
  // generate an XSPF slim player for this playlist
  $player = audio_get_players('name', variable_get('audio_feeds_default_player', 'lacymorrow_xspf_player_slim'));
  $playlist_url = url('node/' . arg(1) .'/xspf', NULL, NULL, TRUE);
  $output .= "<strong>Audio sample:</strong><br>"; 
  $output .= theme($player['theme_xspf'], $playlist_url);
  $output .= "<br>";
  }  
  return $output;
}
}